How Alcohol and Altitude Impact Your Body

The myth that moving from sea level to a higher altitude will make alcohol more functionally potent is pervasive in our society. Many people have been warned about the increasing effects of alcohol when moving to a higher-elevation location. During the 2008 Democratic National Convention, the DNC issued this warning: “Remember that drinks may go to your head faster than you’re used to in New York.” However, the science just doesn’t back that up.

Studies done on alcohol consumption and how altitude affects it have repeatedly debunked the idea. However, changing altitude can affect how you feel when you drink, even if it doesn’t actually make it stronger or change the science behind it. So, where does this myth come from? Does it have any bearing on reality or is it something made up? Let’s examine the source of this myth, the real truth behind the myth that alcohol is more potent at higher altitudes, and look at how altitude affects the way your body processes and reacts to alcoholic drinks.

The research for this article was crucial as it is a heavily scientific topic. We looked at medical journals, peer-reviewed studies, and other reputable sources to determine whether alcohol has increased effects at higher elevations. We also looked at the debunked studies to determine whether the studies had major holes or discrepancies that made them produce results that didn’t align with reality. Finally, we compared the methodologies and results of both debunked and more recent studies to determine where the differences were and whether there were factors in the studies that could cause the differing results. These steps helped us best understand not only the source of the pervasive myth but also the truth behind it.

The myth that alcohol is more potent at higher altitudes is based on a scientific principle, even if the conclusion is fallacious. The idea is that at higher altitudes there is less oxygen in the atmosphere for you to breathe. The myth concludes that the lowered oxygen levels at higher altitudes will impact your body's ability to metabolize and process alcohol, making the alcohol functionally more potent due to the slowed breaking down of the chemical compounds in the liquid.

This myth was then "confirmed" by a loosely scientific study done with minimal research. The head researcher, R.A. McFarland, concluded that the body will metabolize alcohol slower at high altitudes. His study tested the oxidation of alcohol from the body, claiming that only a small percentage of alcohol is metabolized through the kidneys and liver (McFarland, 1930). His idea was that since alcohol's primary method of leaving your body is through oxidation, the lowered oxygen levels at high altitudes would stall the oxidation of alcohol in the body and make you drunker because there would be more time for the alcohol to enter your bloodstream before the body breaks it down.

Essentially, this builds upon a scientifically sound basis. As evidenced by looking at the effects of alcohol as you age, when your body metabolizes alcohol slower you get drunker. When looking at geriatric drinkers, the alcohol they drink stays in their bodies longer. Thus, their blood alcohol levels increase even when they don't increase the amount of alcohol they drink. However, as we mentioned, McFarland's research on this topic was minimal and his hypothesis doesn't actually hold up under rigorous scrutiny.

More recent studies done on the topic of alcohol's effects at different altitudes have contradicted McFarland's original 1930s study. One study done in Austria measured the blood alcohol level of young male alpinists both at sea level and at moderate altitudes. Unlike McFarland's study, this was a randomized, double-blind, placebo-controlled study. The study found that the men's blood alcohol levels after drinking 1 liter of beer at sea level and at a moderate altitude were nearly identical, meaning they were physically no drunker at a high altitude than at sea level.

Additionally, the American Federal Aviation Administration did a series of studies on pilot performance and civilian physical effects at simulated altitudes and with high blood alcohol levels at different altitudes. The first mentioned study concluded that while alcohol and altitude both independently influenced pilots' performances, the cross-interaction was minimal.

A third study took readings on both performance at various tasks and blood alcohol level after consuming alcohol both at sea level and at 12,500 feet in the air. This study found no significant difference between breathalyzer readings at sea level and 12,500 in the air after consuming alcohol. However, they did find moderate changes in the ability to perform tasks after consuming alcohol at different altitudes. This finding suggests that while you are physically not drunker, you are more affected by how drunk you are. This tidbit does suggest that the effects of alcohol might be greater at high altitudes. However, that's not the same as being more drunk. Your blood alcohol level doesn't increase, but your apparent drunkenness does. So, why is that?

One of the primary issues that people face when moving from sea level to a high altitude is increased altitude sickness. The air pressure increases. That means the air around you exerts more force on your body at a high altitude compared to a low one. This disrupts the function of some body systems, such as the inner ear, leading to altitude sickness. Symptoms of altitude sickness include dizziness, light-headedness, difficulty with balance, and vertigo. Sound familiar? Those are the same symptoms a person might experience when drinking alcohol. However, most studies have concluded that the relationship between alcohol and altitude sickness is not significant. Studies on the cross-relationship between the consumption of alcohol and altitude sickness have repeatedly shown that the effects are not strongly connected enough to be considered correlational.

One study of thousands of visitors to the Rocky Mountains actually showed that people who drank alcohol within the first 24 hours of arriving experienced decreased mountain sickness overall. However, it's also worth noting that these results could be skewed. People experiencing severe mountain sickness are unlikely to drink alcohol for fear of exacerbating how sick they already feel. So, the results of that specific study might point to a more survivor-complex-esque result. That is to say that if we look at the symptoms experienced by people who are well enough to drink alcohol within the first 24 hours of arriving in the mountains, we're likely to see the least severe effects and that we might receive different results if we dose sick patients with alcohol at high altitudes.

Hypoxia is when your body, your brain in particular, doesn't have enough oxygen to function normally. It can cause symptoms like confusion, an increased heart rate, difficulty breathing, and bluish skin. At high altitudes, there is less oxygen present in the air. That means every breath you take, even if it's not abnormally small, brings less oxygen into your bloodstream. Thus, as you go up in the atmosphere, the chances of experiencing hypoxia increase because you need to breathe more to reproduce the same amount of oxygen that was in your bloodstream at sea level.

You are already at risk of developing mild to moderate hypoxia just from going too high in the atmosphere because of the air pressure and how that interacts with your ability to breathe the air. In typical, healthy passengers the blood oxygen saturation decreases to as low as 90% when flying. However, it is not because of a lack of oxygen in the air that you can't breathe at high altitudes. It's because the air pressure is so great that you can't breathe it in. This is why patients who have an oxygen saturation of below 92% at sea level require supplemental oxygen when they fly; they are unable to get the oxygen required for life from the surrounding air, even with the pressurized cabin.

Alcohol also reduces your body's ability to process oxygen. As you drink more, your body has more difficulty circulating oxygen through the bloodstream, including to your brain, even if there is enough oxygen to breathe in the air. Hypoxia experienced despite there being adequate oxygen in the air a person is breathing is called "histoxic hypoxia" and the three main causes of histoxic hypoxia in humans are cyanide, alcohol, and narcotics.

Most of the primary ailments caused by alcohol consumption are caused by the cell damage that ethanol inflicts on the body. In small amounts, ethanol causes euphoria, disorientation, and other “high” effects. In large amounts, it kills cells rapidly and can cause severe damage to sensitive organs in the body. Hypoxia, even mild or moderate hypoxia, also causes cell damage when left untreated. This damage is why supplemental oxygen for patients who need it is crucial. Without it, the cell damage can be so severe that it causes terrible health effects for the patient that could kill them prematurely.

A study showed that alcohol-related cell damage increased when patients experienced hypoxia at the same time. This finding suggests that people who drink alcohol at high altitudes suffer from more cell damage than those drinking at low altitudes, even if the amount they drink is the same. Like other studies, the findings suggest that the difference is, at worst, moderate. However, cell damage is a cause of cancer. When scientists refer to a substance as a “carcinogen,” they mean that it causes the type of cell damage that can later become cancer.

Alcohol is one such carcinogenic substance that drinkers should be aware of, especially if they’re in a situation where the cell damage from the alcohol could be increased. Since this type of cell damage can later become cancer, it’s worth considering. One or two drinks at a high altitude probably won’t be the tipping point that gives you cancer. However, if you live at a high altitude, it might be worth cutting back to avoid the potential of cancer growth in your mouth, esophagus, stomach, liver, and kidneys.

Altitude doesn't necessarily affect hangovers the way one might assume. Rather, the effects of altitude on hangovers aren't always a direct cause and effect. Instead, some drinkers may experience more severe hangovers from alcohol at high altitudes because they are also altitude sick. It's kind of like getting a cold while you also have the flu. The cold isn't necessarily making the flu worse in the strictest sense, but you still feel worse than you would if you only had one or the other. There are a few reasons for the disparity in hangovers at different altitudes.

Firstly, at higher altitudes, the air pressure makes it harder for people to get the amount of oxygen they need to thrive. At mild to moderate altitudes, only the most hard-pressed breathers will notice the difference. However, over 12,500 feet everyone starts to feel sicker from the lack of oxygen, though to varying degrees from person to person. The decreased blood oxygen saturation can compound on top of your hangovers to make you feel worse. Additionally, you might feel the compounded effects of altitude sickness on your hangover, making the hangover functionally worse.

Secondly, the air is drier at high altitudes. This drier air means your body is more likely to suffer from dehydration, a common secondary side effect of alcohol. Alcohol is a diuretic, meaning it makes you pee more often. Every time you pee, you release some of your total body water. If you aren't also replenishing your body's water level, the dehydration may make your hangover significantly more painful.

Air at higher altitudes has different humidity from air at sea level. The air high up in the atmosphere is drier than the air close to the surface. It is also at a higher pressure, making it harder for you to absorb the oxygen in the air, even if the oxygen saturation is adequate for breathing. The low oxygen saturation and dry air make you breathe more quickly and more frequently, expelling water in the form of breath vapors with each breath. This process increases how dehydrated you get and makes the dehydration process faster than at sea level.

Dehydration is also an effect of alcohol. As we mentioned above, alcohol is a diuretic, which means it causes you to urinate more often and release more water. You can combat this effect by drinking more water or other hydration-focused liquids while also drinking your alcohol. However, if you fail to drink enough liquids to replenish your total body water, you may experience increased effects of dehydration while drinking, at high altitudes especially.

The combination of losing more water through heavy breathing and alcohol-induced diuresis at the same time can make it more difficult to retain the amount of water needed to feel healthy. Additionally, the primary cause of hangovers is dehydration. This is why drinking Pedialyte or another dehydration aid can help reduce your hangover symptoms. When you drink at a high altitude, the combination of dehydration and altitude sickness can give you a killer hangover. Make sure you're drinking enough clear liquids when drinking at a high altitude and consider keeping a rehydration liquid like Gatorade on hand for the next morning.

Another effect of both alcohol and altitude is a faster heart rate. The air higher up in the atmosphere is thinner and contains less oxygen. These factors mean that each pump of your heart delivers less oxygen to your bloodstream at a high altitude compared to a low one. Alcohol also increases heart rate, especially while sleeping. This increase from alcohol is due to the relaxant effect of the substance. The alcohol relaxes the blood vessel walls, which increases your sleeping heart rate.

A study had 48 total test subjects. They were split into groups, one assigned to a sleep lab and the other to an altitude simulation chamber. The chamber would replicate the air pressure conditions found at high altitudes like the ones experienced when flying. Participants either drank no alcohol before the test or drank alcohol before the test. Then, the researchers monitored their heart rate, blood pressure, and oxygen saturation as they slept for four hours in their designated environment.

The participants who drank alcohol before sleeping in the altitude chamber had their blood oxygen saturation drop to just 85% and their hearts sped up an average of 88 beats per minute to compensate for this drop in O2.

Hypoxic ventilatory adaptation is defined as "a diverse set of physiological responses and behaviors that increase ventilation of respiratory organs such as gills in response to low O2 levels" (Borowiec & Leonard, 2024). All creatures that breathe have some type of hypoxic ventilatory adaptation that triggers when they enter low-oxygen situations. In humans, this typically presents as hastened breathing. Scientifically, your body is adapting to the lower oxygen saturation by increasing ventilation, allowing your body to move smaller quantities of oxygen faster to compensate for the lower quantity of oxygen entering your bloodstream.

Alcohol depresses the central nervous system. One side effect of drinking alcohol is slower breathing due to the depression of the nervous system. Unfortunately, that means that if you drink alcohol while also suffering from hypoxia, your hypoxic ventilatory adaptation may not trigger as strongly. Even if the response triggers in your body, your central nervous system may be unable to adequately compensate for the lost oxygen through increased respiration. At mild altitudes, this may not be significant. However, people with pre-existing breathing conditions and those who are getting older might have a hard time breathing at high altitudes if they drink before they acclimate.

A study done on ten alpinists measured the effects of alcohol on the hypoxic ventilation adaptation in humans at 171 meters above sea level and 3,000 meters above sea level. After drinking alcohol at 3,000 meters above sea level, the subjects’ partial oxygen pressure dropped from 69.0 mm Hg to 64.0 mm Hg and their partial carbon dioxide pressure increased from 32.0 mm Hg to 34.0 mm Hg, a significant statistical change.

Finally, alcohol increases your blood pressure. As much as two drinks per night on average can significantly increase your chances of developing chronic hypertension. Altitude also increases your blood pressure. As we mentioned above, your heart rate increases when you increase your altitude in response to the lowered oxygen environment. When your heart beats faster, your blood pressure increases. This response is normal and helps combat the reduced oxygen saturation from the altitude.

However, when you combine these two effects you can raise your blood pressure to unhealthy levels quickly. Both of these stressors on your heart can raise your blood pressure to the point where it can be damaging in the short and long term, especially if you’re older or have a pre-existing heart or blood pressure condition. Combining them only compounds the effect, making it more pronounced and raising your blood pressure even higher. It’s unlikely that this increased blood pressure, even compounded from multiple sources, will cause you immediate, grievous harm. However, those who are at risk should be careful when drinking at extremely high altitudes. Experts recommend vulnerable persons avoid alcohol consumption in the early stages of altitude acclimation.