Does Alcohol Dilate Pupils?

Alcohol can cause dilated pupils, but at a different rate than other drugs. When people drink alcohol, their pupils dilate slower than they usually do, which can cause blurred vision or tunnel vision.

Why do my pupils dilate when I drink alcohol?

What happens to our eyes when we drink alcohol – We know that alcohol can damage our health, if consumed in excess, but did you know that alcohol can affect your eyesight? Here, we’ll take a look at the links between alcohol and eyesight, examining whether drinking alcohol can actually lead to long-term damage.

Dilated pupils. Because alcohol relaxes muscles all over the body, it causes the pupils to dilate as the muscles in the iris expand. Poor focus. Too much alcohol can affect the way that the muscles in the eye work together and react to signals from the brain – leading to blurry vision and an inability to focus. Slower reactions to light. Normally, when we enter a darkened environment, our eyes dilate to take in more light. Conversely, when we are surrounded by bright light, our pupils contract so as not to damage the retina. However, just as alcohol can affect the speed of our movement and reactions to other stimuli, it can affect the way our eyes react to light – meaning that our eyes can be slow to adapt to sudden bright lights or being plunged into darkness, after we’ve consumed alcohol. This is an effect that will wear off as the body processes the alcohol – so the more you drink, the longer it will last. Have you ever noticed how some people’s eyes turn red or bloodshot when they drink alcohol? That’s down to the blood vessels in the eye expanding as a reaction to the alcohol consumed. Dry eyes. Dry eyes are more likely to occur after drinking alcohol, because it’s a diuretic that makes you dehydrate easily.

What happens to your eyes when you drink alcohol?

Short-Term Effects – Short-term or immediate vision effects of drinking too much can impair your peripheral vision, resulting in tunnel vision. This makes it harder for your pupils to react, so they can’t constrict or dilate properly. Even common tasks, such as driving at night, can become a challenge with the direct impact of headlights decreasing reaction times.

In addition, alcohol has been proven to alter the ability to perceive contrast. Researchers in Australia found that consuming alcohol at their legal limit of 0.05% greatly affected the ability to visually adjust for brightness and contrast. The perception of contrast was reduced by 30% at the legal blood alcohol level.

According to the study, this short-term disability is caused by how our visual system processes contrast or brightness differences, making distinctions between different objects based on lightness and darkness, like stoplights, much more difficult. Other effects of drinking alcohol regularly can result in dry eyes and eyelid twitching, known as myokymia. This triggers short-term inflammation and double vision that causes burning and itching of the eyes, migraines, and sensitivity to light. Long-term symptoms of this effect may cause the blood vessels in your eyes to grow, making your eyes often appear red and bloodshot.

What causes enlarged pupils?

How long will my pupils be dilated? – If you received dilating eye drops from an ophthalmologist, your eyes could be dilated between four and 24 hours. The length of time is dependent on the type of drop used and how your body responds to it. If pupil dilation is the side effect of a medication or drug, the duration may vary based on the type of drug and the dosage taken.

Why does alcohol make my pupils small?

Fentanyl – Fentanyl is a synthetic opioid that has been used in hospitals since the 1960s. This drug previously tended found in patches, lollipops, or nasal sprays and is prescribed for severe pain management. Unfortunately, fentanyl has become increasingly abused in recent years due to its potency.

1. Most fentanyl that is now seen in the US is made in Mexico, with ingredients shipped from China.
2. Cartels then send cut the fentanyl with other ingredients, before sending to the US.
3. People regularly overdose from illicit heroin due to its potency and mistakes made when it is mixed with other substances.

When taken recreationally, this drug can also cause pinpoint pupils and respiratory depression. Alcohol can also cause pupils to vary in size. In cases of chronic alcohol abuse, the eyes may bulge out and appear almost glassy due to the presence of excess fluids.

1. This condition is known as “alcoholic eyes” or “drunken eyes.” Alcohol affects the brain in a variety of ways, including reducing coordination and impairing decision-making.
2. The body responds by producing chemicals that cause the pupils to dilate in order to increase light entering the eyes.
3. If someone drinks enough alcohol to cause themselves liver damage, you may also note yellow-ness in their eyes.

This is caused by a high level of bilirubin. Liver damage can often be halted, as long as the person stops drinking in time. Once cirrhosis (scarring) of the liver occurs, there is no way to restore the liver back to a healthy condition.

Do eyes dilate when in love?

– For starters, oxytocin and dopamine — the “love hormones” — have an effect on pupil size. Your brain gets a boost of these chemicals when you’re sexually or romantically attracted to someone. This surge in hormones appears to make your pupils dilate.

Does dilated pupils mean big or small?

Dilated pupils are pupils that are larger than normal. They are sometimes called dilated eyes, The size of your pupils is controlled by tiny muscles in the colored part of your eye ( iris ) and the amount of light reaching your eyes. In bright light, your pupils constrict (get smaller) to prevent too much light from entering your eyes.

3.35 mm in direct light 3.86 mm in normal room lighting 6.41 mm in near-total darkness

If your pupils are significantly larger than these averages, you have dilated pupils. A dilated pupil can sometimes still react to light — that is, get smaller in bright light or when a light is shined at the eye. But typically, dilated eyes don’t respond normally to light.

1. A large pupil that is completely unresponsive to light is called a “fixed” dilated pupil.
2. Dilated pupils aren’t the same as anisocoria, a common condition where both pupils react normally to light but differ in size by about a half-millimeter or more.
3. Anisocoria is benign and affects about 20% of the population.

SEE RELATED: Small pupils: What do they mean?

Do your pupils seem larger than normal?

If you’ve noticed your eyes are unusually dilated (larger) or one eye is dilated more than the other, call an eye doctor ! It’s normal for your pupils to dilate more the darker your surroundings. However, if your eyes are fully dilated even in a bright environment or if your eyes don’t seem to be dilating as they should, it’s time to get your eyes checked. Your pupils should also dilate symmetrically. If one pupil is noticeably larger than the other, you may have something called anisocoria, An eye doctor can help.

Do your eyes look different when you’re drunk?

Alcohol causes the blood vessels in your eyes to get larger and fill with blood, which creates a red, bloodshot appearance. Your eyes might also get dry and irritated when you drink because alcohol is a diuretic, meaning it makes you need to urinate more frequently.

Do your eyes change when you drink?

You’re feeling a bit blurry, your vision is going in and out of focus you think you’re getting some double vision Do you need new glasses? Or could it be that you just had one too many glasses – of wine? Around the world, about 117 billion gallons of alcoholic beverages are consumed each year.

In the US, beer is the drink of choice, followed by spirits and wine. However, while a tipple or two at a party is generally considered socially acceptable, a number of Americans rely on having a bottle in hand for a bit more than just to look cool or to wet their lips. In 2019, the National Survey on Drug Use and Health estimated around 14.5 million US residents were living with an alcohol addiction.

While the full effects of alcoholism are beyond the scope of this particular article, there are some interesting facts to know about the effect alcohol has on eyes. Here are 6 ways that drinking alcohol affects your eyes: 1. Slows your pupillary reactions The pupil is the opening in the middle of your iris, which is the colored part at the front of your eye.

The iris is a muscle that can dilate the pupil (making it larger) or constrict it (making it smaller). The ability to dilate and constrict is important because it’s your eye’s reflexive way of controlling how much light gets through. Ever had a bright light suddenly shine right into your eyes? It’s not comfortable and you were probably temporarily blinded.

Alcohol consumption causes the iris muscles to relax, resulting in a dilated pupil. It also results in a slowing of your pupil reflexes, which delays your pupils’ ability to constrict in the presence of increased light. Although this may not be too much of an issue in most circumstances, it can cause driving at night to become dangerous as your eyes will not be able to react as quickly when faced with oncoming headlights.2.

1. Impairs your contrast sensitivity Contrast sensitivity is the ability to discern differences in shades and patterns.
2. For example, you need better contrast sensitivity when driving on an especially gray and rainy day, trying to pick out the silver sedan with the broken taillights in front of you through sheets of rain.

Alcohol intoxication is known to cause impaired contrast sensitivity, making it all the more difficult to see properly in those difficult conditions, such as heavy rain or twilight.3. May exacerbate dry eye disease (DED) Different studies report conflicting outcomes on the effects of alcohol on DED.

1. Dry eye disease, or DED, is characterized by inflammation on the surface of the eye and a compromised tear film.
2. It often manifests as the eyes feeling dry (obviously) but is also associated with other symptoms such as gritty or burning eyes, feeling like there’s a foreign particle stuck in your eye, redness, and variable vision.

Many studies have concluded that alcohol consumption can worsen the signs and symptoms of DED. Low levels of alcohol have been detected in the tears for a short period after having a drink and are linked to increased dry eye symptoms. However, a recent study noticed that alcohol was a risk for DED only in females – and in males, alcohol intake actually had a protective effect against dry eye.

1. One explanation for this put forth by the researchers was the effects of differences in sex hormones between men and women, particularly androgens, which are found in higher levels in men.4.
2. May increase your risk of cataracts Cataracts are an opacity in the lens of the eye, which hinders the passage of light.

Among other symptoms, this results in blurry, foggy vision. The only way to treat a cataract is through surgical removal. While age-related cataracts happen to the best of us, heavy drinking has been linked to a significant increased risk in their development.

1. In this same study, moderate alcohol consumption was found to be unrelated.
2. Moreover, there is some emerging evidence that moderate drinking may actually help to protect against the development of a cataract requiring surgery.
3. Coming out on top of the list of best beverages for this was red wine (fun fact: almost 25% of red wine consumption in the US is merlot).

While the exact causes of age-related cataract formation are still not fully understood, many doctors believe oxidative stress to be a big contributing factor. The skin of grapes found in wine are known to be full of healthy antioxidants, which may serve to protect against the oxidative damage in the eye’s lens.

• One recent study reported that people who drank 6.5 standard glasses of wine per week were less likely to need cataract surgery.5.
• May increase your risk of age-related macular degeneration (AMD) In the US, age-related macular degeneration, or AMD, is the number 1 leading cause of legal blindness in those of Caucasian descent, the fifth leading cause in African Americans, and the second top cause in those of Hispanic heritage.

The macula is a crucial part of the eye essential for your central vision and ability to discern fine details. AMD is a progressive, irreversible deterioration of the macula, resulting in permanent central vision loss. Although the exact reasons why are unclear, numerous studies have found a link between alcohol consumption and the development of AMD.

• Having more than two standard drinks per day can increase your likelihood of early AMD by approximately 20%.6.
• May increase your risk of glaucoma and elevated eye pressures Glaucoma is an irreversible disease of the optic nerve, which is crucial for vision.
• In many cases, glaucoma is associated with high pressures in the eye, known as intraocular pressure (IOP).

The symptoms of glaucoma are typically painless and difficult to detect until the disease is already advanced. During glaucoma, progressive optic nerve damage results in gradual and permanent loss of your peripheral vision. The impact of drinking on IOP is not fully understood, with different studies reporting completely opposite results.

Some researchers have noted that drinking alcohol is linked with higher IOP – interestingly, this association was found only in men and not women. Conversely, there are some studies that have found that alcohol can actually temporarily reduce IOP, providing some protection against glaucoma. And then there are the studies that fall somewhere in the middle, reporting that there is no relationship between drinking and IOP.

At this point in time, much more work needs to be done to really figure out whether eyecare practitioners should start recommending for or against alcohol as an accompaniment to meals. In the meantime, you can’t go wrong by following the Centers for Disease Prevention and Control drinking guidelines: you can choose not to drink, otherwise drink in moderation by limiting your daily intake to no more than 2 drinks for men or 1 drink for women.

Why are my daughters pupils so big?

Seeing a pattern – Over the past two years, Glen Steele, O.D., has been tracking a marked increase in the magnitude of changes in pupil size and the number of children showing this pattern. An increase in pupil size does not happen in isolation, Dr. Steele says, so he also was concerned about what was happening with other body processes, such as accelerated heart rates, widened bronchial passageways, constricted blood vessels, perspiration and raised blood pressure.

He has linked this to children’s use of cellphones and tablets. He is not alone. “There are many individuals, groups and organizations looking at this phenomenon,” says Dr. Steele, long-time advocate for children’s vision. He has taught and provided patient care at Southern College of Optometry in Memphis, Tennessee, for 50 years.

In particular, Dr. Steele has taken note of enlarged pupils—extremely large pupils between 7 and 10 millimeters that may respond to light but not to accommodation—among some of the younger patients he sees. Enlarged or dilated pupils can be caused by a number of factors: medications, drug use, eye and brain injuries, recreational drug use and eye diseases.

1. But the consistent factor among his patients, he says, appears to be prolonged phone or tablet use.
2. In past years, I would see maybe one congenitally large pupil a semester,” Dr.
3. Steele says.
4. Now I see five or six a day in a pediatric population (our clinic defines pediatric as birth to 12 years of age).

This is a significant change in the number seen in a very short time frame. I have tried to link it to medications and other things but the most consistent has been device use. “I call this pattern of large pupil size defocus,” he says. “Pupils are smaller during focus and larger during defocus.

1. One can imagine how a pattern of defocus could interfere with the ability to perform in the classroom and other activities requiring focus, such as school work.
2. Because I have only noticed this pattern for the past 18 months to two years, I do not know what the long-term effects will be as there has been very little time to study it and its effects on other sympathetic body processes.

“Defocus only occurs when we’re scanning on social media or gaming,” Dr. Steele says. “If reading, there is more tendency to focus, but it is easy to tell when I walk into the room and take a look at pupils with my retinoscope. It is more scanning during social media or playing a game, in which you have to be aware of the ‘attackers’ in a video game coming from all directions.

1. You can’t stop and look at them or something will attack you from another direction.
2. This is the origin of the defocus pattern.
3. When this pattern is present, one must suspect some type of video game syndrome,” he says.
4. The problem is not in the eye directly, but it is affecting sympathetic responses that are shown in the eye.” Other ocular and developmental consequences from extended screen time, according to Dr.

Steele, include:

Reduced stereopsis (depth perception). Reduced ability in accommodation testing. Even though the patient may respond to the plus or minus with accommodation, pupil size changes minimally. Does not show expected visual acuity during refraction testing. Reduced fine motor control when learning to write, depending on a child’s age. Reduced social interaction. The addictive patterns are similar to other addictions and are reaching alarming status.

Can anxiety cause dilated pupils?

How Anxiety Can Affects the Pupil of Your Eye People think of anxiety as a mental condition. But anxiety affects your body as well. During periods of intense anxiety – especially during panic attacks – your entire body goes into fight or flight mode, and you go through some immediate physical changes as a response.

How long do eyes stay dilated?

It typically takes around 4 to 24 hours for eye dilation to wear off completely. This duration varies depending on a few factors, which include the following: Eye color: The effects of eye dilation usually last longer on lighter-colored eyes, such as blue or green ones, than on darker-colored eyes.

Do pupils dilate when tired?

How Pupil Size Relates to Sleep Loss – Research has shown that there is a strong relationship between sleep deprivation, pupil size, and pupil stability. A well-rested individual can maintain constant pupil size in darkness for 15 minutes. As you become more sleep deprived, your pupil size will become less stable.

It fluctuates (or oscillates), becoming subtly bigger and smaller rather than maintaining its size.   Moreover, your pupils’ overall size will shrink, perhaps reflecting fatigue in the task of maintaining the larger size. The muscles themselves may tire and the ability to keep the pupil open may fade.

Therefore, both pupil size and stability can objectively identify sleepiness and sleep deprivation.   This might be useful to ensure adequate rest is attained and that the consequences of sleep loss do not occur.

How long does it take for dilated eyes to return to normal?

Dilation is part of a thorough eye exam, You may think it’s a hassle. But it gives your doctor a good look inside your eye, It’s especially important if you’re having eye pain or vision problems, or if you’re more likely to get certain eye diseases. Normally, your pupil gets smaller when light shines into it.

• In dilation, your doctor uses special eye drops to force the pupil to stay open.
• This allows them to see much more of the back of your eye, including the entire retina, the part of the retina called the macula, and the optic nerve.
• During a dilated exam, your doctor can spot problems like a torn or detached retina or an eye tumor.

They can also diagnose and monitor common eye diseases that can take away your sight:

Diabetic retinopathy : Signs include blood vessels that leak, swell, or grow abnormally in the retina. Glaucoma : Your doctor looks for damage to the optic nerve. Age-related macular degeneration : Protein or pigment buildup and unusual growth of blood vessels are symptoms of a breakdown of the macula. Cataract: A clouding of your natural lens.

Almost all of these conditions are painless, so you may not even know you have one unless you see your doctor and have your eyes dilated. Everyone’s eyes react differently to the dilation drops. It usually takes 15 to 30 minutes for your pupils to open completely.

1. Most people are back to normal within about 4 to 6 hours.
2. But for you, the effects could wear off more quickly, or they could last much longer.
3. Certain strengths of dilating drops may lost longer than others.
4. Dilation doesn’t typically affect your distance vision, unless you are farsighted and don’t have glasses to correct your vision.

But because your pupils can’t control the amount of light going into your eyes, the glare outside may bother you. For some people, that makes it unsafe to drive. If you’ve never had your eyes dilated, get someone else to drive you home from your appointment.

Once you’ve had it done, you’ll know whether dilation means you can’t drive after an exam. Whether or not you get behind the wheel, it’s a good idea to bring sunglasses with you so you can shield your eyes after the exam. Dilating drops make it hard for your eyes to focus on things close to you. You probably won’t be able to read, use the computer, or do other tasks that require near vision after your appointment, unless you wear bifocals or use reading glasses.

If you work outside, the bright light may bother you. It may be easier to make an appointment later in the day so you don’t have to go back to work. The National Eye Institute recommends everyone over 60 have a dilated exam once a year. If you’re African-American, you’re at higher risk for glaucoma, so the yearly recommendation starts at age 40.

If you have diabetes, you should also have a dilated exam once a year no matter how old you are. Dilation is often a normal part of an eye exam for people who wear glasses or contacts. But if you’re young and your eyes are healthy, you may not need it every time. Your doctor also may be able to use other methods to check your retina without dilating your eyes, but they may not work as well.

See what your doctor recommends. Many eye diseases are more common as you get older. The American Academy of Ophthalmology says everyone should get a baseline exam with dilation when they’re 40. That way, your doctor can track any changes that could signal a problem.

Do pupils always dilate with attraction?

Do your pupils dilate when you look at someone you are attracted to? – The short answer is yes. Eye contact has been a central part of human interaction for a long time, so it’s no surprise that a change in emotion could cause the pupil to dilate. has found that heterosexual men are more attracted to women when their pupils are dilated.

Being shown two photos of the same woman where the size of pupils have been altered to be different in each, men found women with larger pupils to be more attractive and open. The men described the woman with bigger pupils as “soft”, “pretty” and “feminine”, while characterising the woman with the reduced pupils as “hard”, “cold” and “selfish”.

It should be noted that none of the men noticed the detail change in the photos. Other studies have also found that dilated pupils can be a, and that size and darkness can be used to determine, However, researchers have also found that women don’t respond to pupil dilation the same way as men.

What do large pupils mean?

You look in the mirror and notice that the dark circles in the middle of your eyes are bigger than usual. What’s going on? Those dark circles are your pupils, the openings that let light enter your eye so you can see. Muscles in the colored part of your eye, called the iris, control your pupil size. Sometimes your pupils can dilate without any change in the light. The medical term for it is mydriasis. Medicines, injuries, and diseases can all cause this eye condition. A few medicines can affect the muscles that control your pupils and prevent them from getting smaller when light shines in. These meds include:

Atropine ( Atropen ), which treats problems with heart rhythm, stomach issues, and some types of poisoning Antihistamines, like diphenhydramine ( Benadryl, Genahist, Naramin, Sominex, Unisom ) Decongestants, like pseudoephedrine ( Afrinol, Sudafed ) Motion sickness and anti- nausea medicines such as dimenhydrinate ( Dramamine ) or a scopolamine patchParkinson’s medications such as amantadine ( Symmetrel ) and carbidopa-levodopa ( Sinemet ) Tricyclic antidepressants like amitriptyline ( Elavil ) and desipramine ( Norpramin ) Botulinum toxin ( Botox, Myobloc )Anti- seizure drugs, such as phenobarbital ( Luminal ) and topiramate ( Topamax )

Dilated pupils are one sign that someone has used illegal drugs, such as:

Cocaine Amphetamines LSD Ecstasy

These drugs affect the muscle that widens the pupil, slowing how it reacts to light. So even in a bright room, the eyes stay dilated. Withdrawal from these drugs can also make the pupils stay open wide. Pressure that builds inside your brain after a head injury, stroke, or tumor can damage the muscles in your iris that normally make your pupils open and close.

• One or both of your pupils can become fixed in the dilated position and can’t react to light.
• If that happens, you should see a doctor right away.
• If you’ve had a head injury, your doctor or nurse might shine a light into your eye during the exam to see if your pupils get smaller.
• An eye injury can damage nerves or the muscles in your iris that control your pupil size.

That can also happen after eye surgery, such as cataract removal or corneal transplant, This condition means only one pupil is dilated. It’s called “benign” because it’s not related to any serious conditions, but it can sometimes affect young women who get migraines.

• The pupil usually goes back to normal size within a few hours, but it can last for several days.
• You should still see your doctor to rule out anything serious.
• See your doctor or eye specialist for an exam if your pupils are enlarged and they don’t get smaller in bright light.
• Get emergency help if you’ve had a head injury and your pupils look larger – especially if one pupil is bigger than the other.

The doctor will examine your eyes. You might also have imaging tests such as computed tomography (CT) or magnetic resonance imaging (MRI) scans to look for an injury or other problems in your brain, If a medicine caused your pupils to dilate, they should go back to normal once the drug wears off.

Try to avoid the drug in the future, if you can. If you need the medication for a health problem, ask your doctor if there’s a different drug you can try that won’t affect your eyes. While your eyes are dilated, they will be more sensitive to light than usual. Try to avoid bright places. Wear sunglasses when you go outside.

Sometimes dilated pupils can affect your vision, Ask your eye doctor if you need to avoid driving until your pupils go back to their normal size.

What do small pupils mean?

There are several reasons that your pupils might constrict, leading to “pinpoints” that are two millimeters or smaller. Small pupils can be due to bright light, an emotional response, or looking at something far away. There are six health risks that can cause pinpoint pupils, or miosis.

How much do pupils dilate when attracted to someone?

Much as 45%!

How big is too big for pupils?

A fully dilated pupil is typically in the 4 to 8 millimeters in size, while a constricted pupil is in the 2 to 4 mm range. According to the American Academy of Ophthalmology, pupils generally range in size from 2 to 8 mm.

Do pupils constrict when angry?

Behavioral Characteristics –

• Facial expressions: eyelids tensely narrowed, eyes glaring, pupils constricted, mouth open, grin tense, lips retracted, teeth clenched, face red, veins distended, nostrils widened, jaw jutting, expression frowning.
• Body Stance: head toward object, “attack,” muscles tense, fists clenched, gestures quick and forceful.
• Speech: very controlled, precise and hesitating OR forceful, loud, high-pitched, loud cursing, inappropriate, mirthless laughter, threatening tone, shouting, sarcastic, sullen tone.
• Actions: restlessness, pacing, stony withdrawal, negative responses to rules and requests, hitting, destroying property,direct verbal warnings, driving recklessly, excessive friendliness, ingratiating attitude, joking at the expense of others,forgetting names and appointments, being late, mutilating, killing, suicide.

2

Does alcohol cause pupils to contract?

Short-term vision-altering effects –

Slower pupil reaction. Alcohol causes the iris to constrict and dilate at a much slower speed, This becomes an issue for drivers who have been drinking as they cannot adapt as quickly to oncoming headlights. Decreased contrast sensitivity. Being able to make distinctions between different objects based on lightness and darkness, a very important ability when driving at twilight, is impaired by alcohol. A new study from Western University in Ontario, Canada shows alcohol reduces the ability of the eye to adjust vision for brightness and contrast by 30 percent at a blood alcohol level around the legal driving limit. Eye twitching. Eye twitching (myokymia), which is actually the eyelid twitching, can be triggered by excessive alcohol intake, Increased dryness. Findings from a study by the Hallym University College of Medicine suggest consuming even a small amount of alcohol can increase and exacerbate symptoms of dry eye.

Does alcohol affect the reflex action of the eyes True or false?

Slow Pupil Reaction Time – Drinking alcohol affects the reflex action of the eyes. Chronic alcohol abuse affects how quickly your pupils can dilate or adjust to brighter and darker settings. When your pupils are unable to dilate or contract, it’s difficult to adjust to bright settings, see in a dark room, and differentiate between colors.

Why do my eyes twitch when I drink alcohol?

5) Overindulging In Alcohol And Tobacco – Alcohol can cause eye twitching because it usually relaxes all the muscles in the body once consumed. Cigarette smoking on the other hand relaxes your skeletal muscles, while stimulating the heart. In both cases, the muscles in the eyelids end up being exhausted, which can be one of the possible causes.

Does alcohol dilate or constrict blood vessels?

Vascular actions – The action of alcohol on the vasculature is variable according to its concentration and the kind of blood vessel.25, 26 High concentrations of alcohol constrict most blood vessels. This vasoconstriction depends on calcium ions and is inhibited by calcium channel blockers.

Alcohol also acts to augment the vasoconstriction caused by catecholamines and vasopressin and inhibits endothelium-dependent vasodilation.27, 28 It has been suggested that endothelin and nitric oxide are involved in alcohol-induced vasoconstriction.29 Soardo et al.30 observed that alcohol increased the levels of endothelin-1, nitric oxide, plasminogen activator inhibitor-1 and oxidative stress both in vivo and in vitro,

As the scavengers of oxidants prevented those changes, oxidative stress may have a role in the alcohol-induced endothelial dysfunction.30 It was, however, reported that the flow-mediated dilation of the brachial artery and blood markers of endothelial function were similar between the usual drinking period and the alcohol restriction period in healthy men.31 On the other hand, low concentrations of alcohol usually dilate blood vessels.25, 26 This effect also seems to be mediated by calcium ions and endothelium-derived nitric oxide.

1. It has been shown that low doses of alcohol increase the release of nitric oxide and augment endothelium-dependent vasodilation.32 Criscione et al.27 reported that ethanol inhibits norepinephrine-induced vasoconstriction in the rat mesenteric artery.
2. They also observed that norepinephrine-induced vasoconstriction is enhanced after the withdrawal of alcohol.

These results seem to be consistent with the time-dependent BP changes after alcohol consumption in humans. Acetaldehyde, a metabolite of alcohol, acts as a vasodilator.17 Subjects with low-active aldehyde dehydrogenase (ALDH2 * 2) show facial flush after alcohol ingestion because of the accumulation of acetaldehyde in the blood.

Such subjects, especially those homozygous for the ALDH2 * 2 genotype, show marked tachycardia and hypotension after alcohol consumption.3, 23 In our study, the alcohol-induced BP reduction in hypertensive patients was due to a decrease in peripheral vascular resistance ( Table 1 ).7 We also observed that the intracellular sodium concentration in red blood cells decreases after alcohol ingestion.33 This change may also act to dilate blood vessels through a decrease in the intracellular calcium concentration.

Table 1 Hemodynamic variables after alcohol intake in hypertensive patients (adopted from Kawano et al. with permission) Taken together, alcohol has both constrictive and dilative actions on blood vessels, and these effects may be dependent on race, the dose and timing of alcohol consumption.