Are you planning a trip to the mountains? Do you know what altitude sickness is? Join us as we explore the signs and symptoms of altitude sickness, how to prevent it, and how to handle it if you experience it.

What is Altitude Sickness?


Altitude sickness is a group of symptoms that can occur when a person is exposed to high altitudes, usually above 2,500 meters. It is also sometimes called “mountain sickness” and is caused by a lack of oxygen in the air at higher altitudes.

The body may not have had enough time to adjust to the reduced oxygen levels and changes in air pressure, leading to symptoms such as headache, nausea, vomiting, dizziness, and fatigue.

It can cause severe brain swelling (high-altitude cerebral edema). Altitude sickness is more likely to occur if you ascend too quickly, but it can also happen if you stay at high altitudes for long periods.

What Causes of Altitude Sickness

Altitude sickness is caused by ascending too rapidly, which doesn’t allow the body enough time to adjust to reduced oxygen and changes in air pressure. It occurs when the body has not had time to adjust to less oxygen available in the air at altitudes above about 2,500 meters.

It can be caused by various factors, including rapid ascents, low oxygen levels at high altitudes, dehydration, overexertion, cold temperatures, and lack of acclimatization. As you ascend to higher altitudes, the air pressure decreases, meaning less oxygen is available for your body. This can cause the body to become stressed and unable to function properly.

Symptoms of AMS include headache, nausea, shortness of breath, fatigue, and dizziness. It is important to recognize the symptoms and take steps to prevent or treat altitude sickness to avoid more serious complications.

The symptoms of altitude sickness

Altitude sickness can range from mild headaches or nausea to more severe symptoms like brain swelling, confusion, lung fluid, difficulty breathing, and even death.

About 20% of people will develop mild altitude sickness after ascending to 2,000 meters or more heights. After 4,200 meters (13,800 feet), most people will experience some degree of altitude sickness.

Most persons who suffer from altitude sickness get AMS or acute mountain sickness. Moreover, at 10,000 feet above sea level, 75% of persons will experience minor symptoms. AMS is classified into three types:

  • Mild AMS: Symptoms such as a mild headache and tiredness do not impede daily activities. After a few days, your symptoms will improve as your body adjusts. As your body adjusts, you should be able to stay at your present height.
  • Moderate AMS: Symptoms begin to obstruct your activities. You may feel severe headaches, nausea, and difficulties coordinating your movements. To feel better, you’ll need to descend.
  • Severe AMS: Even at rest, you may feel short of breath. Walking can be challenging. You must immediately descend to a lower altitude and seek medical attention.

Altitude sickness complications

Severe types of altitude sickness can develop at exceedingly high altitudes. The two most severe types of altitude sickness are pulmonary edema (fluid in the lungs) and cerebral edema (fluid in the brain) (swelling of the brain).

High altitude pulmonary edema is known as “High Altitude Pulmonary Edema” (HAPE), while cerebral edema is known as “High Altitude Cerebral Edema” (HACE).

HAPE and HACE are potentially fatal conditions, and a steroid called dexamethasone can relieve symptoms until the affected person can descend to a lower altitude. Many of the lesser altitude sickness symptoms may be handled without descending.

This decline may generally be avoided with rest, medication to treat symptoms, and enough fluids to prevent dehydration.

High altitude cerebral edema (HACE)

High altitude cerebral edema (HACE) is swelling of the brain induced by a lack of oxygen.

HACE symptoms include: 

  • weakness
  • Being unwell and feeling sick
  • Coordination problems
  • feeling confused
  • Experienced hallucinations

A person suffering from HACE may be unaware that they are unwell. They may argue that they are OK and wish to be left undisturbed. HACE can manifest itself in a matter of hours. If not treated quickly, it can be deadly.

HACE Treatment

  • Descends to a lower altitude.
  • Dexamethasone should be taken
  • If available, provide bottled oxygen.

Dexamethasone is a steroid medication that lowers brain swelling. Professional mountain climbers frequently carry it as part of their medical equipment. If you can’t get down immediately, dexamethasone can help ease discomfort until you can.

You should seek medical attention as soon as possible for further treatment.

High altitude pulmonary edema (HAPE)

Fluid buildup in the lungs is known as high-altitude pulmonary edema (HAPE).

HAPE symptoms include:

  • Cyanosis: a blue tinge to the skin or lips (cyanosis)
  • breathing difficulties even while resting.
  • Chest constriction
  • A prolonged cough that produces pink or white foamy fluids (sputum).
  • Fatigue and weak.

HAPE symptoms might occur a few days after arriving at a high altitude. If not treated quickly, it can be deadly.

HAPE Treatment:

  • Quickly descends to a lower altitude.
  • Use nifedipine.
  • If available, provide bottled oxygen.

Nifedipine is a medication that helps to relieve chest stiffness and improve breathing. It is also frequently included in the medical supplies of an expedition.

You should seek medical attention as soon as possible for further treatment.

Who is at risk of getting altitude sickness?

Altitude sickness can affect anyone, regardless of age, gender, or fitness level. However, certain factors can increase the risk of developing altitude sickness. Those who are most vulnerable include:

  • People who ascend to high altitudes quickly
  • People who have had altitude sickness before
  • People with a history of heart or lung diseases
  • People with low hemoglobin levels
  • People who are dehydrated or sleep deprived
  • People who engage in strenuous activities at high altitudes
  • People who stay at high altitudes for longer periods of time
  • People with weakened immune systems

It is important to be aware of these risk factors and take the necessary precautions to protect yourself when traveling to high altitudes.

Fit young men are at a higher risk of altitude sickness than others. This may appear unusual, but a very good explanation exists. If a person rapidly ascends, altitude sickness is more likely to occur.

People who are overconfident in their fitness and abilities tend to assume they are unlikely to acquire altitude sickness and ascend more quickly, increasing their chances of experiencing altitude sickness.

If you’ve already had altitude sickness, talk to your doctor about preventative and treatment options before your next trip.

Tips for Avoiding High altitudes if You are Prone to Altitude Illnesses

If you are prone to altitude illnesses, there are a few things you should do to avoid high altitudes. It is important to be aware of your body’s limits and never push yourself too hard.

Monitor your symptoms and take note of any changes. If you start to experience any symptoms of altitude sickness, stop your ascent and descend immediately. Avoid strenuous activities and rest until you feel better.

You should also consider taking medication like acetazolamide to reduce your symptoms and help with acclimatization. In addition, make sure to stay hydrated, eat well, and get adequate rest when climbing at high altitudes. Taking these steps will help you to avoid the dangers of altitude sickness.


It’s most likely altitude sickness if you experience a headache and at least one additional symptom within 24 to 48 hours after relocating to a higher elevation. If you’re ascending, a more experienced climber may detect indications of altitude sickness and point you in the right direction for assistance.

A healthcare specialist will inquire about your symptoms, activities, and location if you have serious altitude sickness. The provider may do a physical exam, including listening to your chest.

A chest X-ray may be required to determine whether or not there is fluid in your chest. In extreme circumstances, your doctor may request a brain MRI or CT scan to look for fluid in the brain.

Preventing altitude sickness

mountain hiking

The faster a person ascends and pushes harder, the higher the chances of developing altitude sickness. This also increases the chances of developing more severe altitude sickness.

New research is revealing the usefulness of Viagra in the treatment of altitude sickness, but no conclusions have been made. Following the advice listed below is the best way to avoid altitude sickness.

  • The only way to avoid altitude sickness is to ascend gradually. After ascending 3,000 meters (9,840 feet) or more, the basic rule of thumb is to not rise more than 300 meters (980 feet) every day.
  • Avoid strenuous activity during the first 24 hours. Skiing, climbing, or trekking during the first 24 hours reduces the likelihood of acquiring altitude sickness.
  • While at high elevations, do not consume alcohol or use smoke. Tobacco inhibits oxygen exchange, increasing shortness of breath and respiratory problems. Alcohol can induce severe dehydration. Altitude sickness can be exacerbated by alcohol and cigarette use.
  • Maintain appropriate hydration. Altitude sickness at high elevations is accelerated by dehydration at high elevations. Begin drinking plenty of water before ascending to high altitudes. If you land in a high-altitude place while dehydrated, you have an increased probability of acquiring altitude sickness or worsening altitude sickness.
  • If you must fly or drive somewhere and are unable to spend time in lowland areas along the route, the medicine acetazolamide can help accelerate acclimatization.
  • If you walk, trek, or climb more than 10,000 feet, go only up 1,000 feet every day. Rest at that height for at least a day for every 3,000 feet climbed.
  • Ascend high and sleep low: If you have to climb more than 1,000 feet in a day, be sure you return to a lower altitude to rest.

Treating high altitude sickness

mountain hiking

There is only one way to treat altitude sickness, which is decent. Most mild cases of altitude sickness can be treated without descent, but descent is required if symptoms do not subside or worsen.

Severe altitude sicknesses, such as HAPE or HACE, are life-threatening situations requiring medical attention and descent ASAP.

Trekking in high-altitude areas, such as Tibet in the Himalayas or South America, can be very adventurous. Still, medical emergencies in foreign countries can be extremely costly and turn an adventure into a disaster.

Seek medical advice before you leave, and if you develop altitude sickness and you are not sure what to do, contact a medical professional before severe altitude sickness develops.

Things to keep in mind

  • Mountain climbers are susceptible to altitude sickness.

Altitude sickness is induced by fast climbing, which does not give the body enough time to acclimate to decreased oxygen and changes in air pressure.

  • Among the symptoms are headache, vomiting, sleeplessness, and decreased performance and coordination.
  • Fluid can accumulate within the lungs, brain, or both in extreme instances, which can be deadly.
  • Descending promptly, drugs, and using oxygen delivered from a handheld container are all alternatives for first aid.

Frequently asked questions

Is altitude sickness harmful in the long run?

Altitude sickness has no long-term detrimental consequences if you take precautions and relocate to a lower height when you get symptoms. You’ll be OK in just a few days. You can continue to go to higher elevations after you feel better as long as you do so gently and safely.

Is it possible for altitude sickness to be fatal?

Altitude sickness can be deadly in rare situations. If you have HAPE or HACE, you may have problems such as coma or even death. To lower your risk, seek therapy as soon as possible.

Is it possible to recover from altitude sickness?

Altitude sickness is only short-lived. You’ll feel better after you return to a lower altitude. Travel slowly when you resume your ascent (or on your next climb) to allow your body to adapt.