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Acute Mountain Sickness

Acute Mountain Sickness (AMS)

What is Acute Mountain Sickness?

Acute mountain sickness is an illness, that can affect mountain climbers, hikers, skiers, or adventure travelers, who are planning to visit high-altitude places like Ladakh. Usually, AMS is triggered above the altitude of 8000 feet (2400 meters). 

AMS is also known as altitude sickness or high altitude pulmonary edema. Dizziness, nausea, headaches, and shortness of breath are a few basic symptoms of this condition.

Primary symptoms of altitude sickness are mild and heal quickly. In very rare cases, altitude sickness can become severe and cause complications with the lungs or brain.

The faster you climb to a higher altitude, you’re more likely to get acute mountain sickness.

Altitude sickness AMS

What causes Acute Mountain Sickness?

Acute mountain sickness is caused by reduced air pressure and lowers oxygen levels at high altitudes. Higher altitudes have lower levels of oxygen and decreased air pressure. When you rapidly travel from a lower altitude to a higher altitude. Your body may not have enough time to adjust to such an altitude change. This can result in acute mountain sickness. Your level of exertion also plays a major role. Pushing yourself towards a high mountain may cause acute mountain sickness.

As altitude increases, the available amount of oxygen to sustain mental and physical alertness decreases with the overall air pressure. Dehydration due to the higher rate of water vapor loss from the lungs at higher altitudes may also contribute to the symptoms of AMS.

Oxygen level

What are the symptoms of acute mountain sickness?

The symptoms of acute mountain sickness generally appear within a few hours after moving to higher altitudes. They may vary depending on the severity of your condition & from person to person. Symptoms often manifest themselves six to ten hours after ascent and generally subside in one or two days, but they occasionally develop into more serious conditions. 

Symptoms include dizziness, headache, muscle aches, insomnia, nausea and vomiting, irritability, loss of appetite, swelling of the hands, feet, and face, rapid heartbeat, and shortness of breath with physical exertion. In severe cases, individuals may lack the energy to care for themselves (like eat, drink, dress, etc.) and slip into a coma or in the worse case, death.

Who is at the risk for acute mountain sickness?

If you live at, or near sea level and suddenly travel to a high altitude, then your risk of having acute mountain sickness is higher. Other risk factors include:

  • If you ascend quickly.
  • If you have not acclimatized to the altitude.
  • A low red blood cell count due to anemia.
  • Alcohol or other substances have interfered with acclimatization.
  • If you have medical problems involving the heart, nervous system, or lungs.
  • A person taking medications like sleeping pills, pain relievers, or any other narcotic medicine, can face AMS too.

How to prevent & treat acute mountain sickness?

Prevention of AMS

The best way to avoid AMS is to prepare your body for higher altitudes at least 2-3 months before you travel. The best way to do this is by  Jogging, cycling, swimming, etc. And you can also do Yoga & breathing exercises like Pranayama. Once you start your journey, it’s advisable to take halts at different altitudes, for a significant period of time. Ideally, you should spend some time at a particular altitude. 

Unfortunately, this can be quite difficult for bikers or tourists, who don’t have much time. If possible, try to arrive at high altitudes, a few days earlier to assist with your body’s acclimatization process. Also, try to sleep at a place at a lower altitude whenever possible. While ascending, do not drink alcoholDrink plenty of fluids & eat regular meals that are high in carbohydrates. You should avoid visiting places, with high altitudes if you have a heart or lung disease.

Treatment of AMS

Treatment for acute mountain sickness varies depending on its severity. You might be able to avoid complications by simply returning to a lower altitude. You should receive oxygen if you have breathing issues. You should not ascend any further if your symptoms continue to worsen. Typically, symptoms will usually improve within 48 hours

Acute Mountain Sickness, AMS


For Acute Mountain Sickness AMS, the use of a medication called acetazolamide (also called Diamox), dosed at 125 -250 mg twice a day can help speed acclimation. Diamox helps you by making you acclimatize faster. It makes you breathe faster and deeper, by taking in more oxygen. It also thins your blood, making it easier for your heart to pump oxygenated blood to parts of your body.

High Altitude Pulmonary Edema, HAPE

Another serious complication is High Altitude Pulmonary Edema HAPE. HAPE is an advanced and more dangerous form of AMS. Pulmonary edema is when there’s high pressure in your lungs. It causes your body fluids to accumulate in your lungs. To cure it, you may need Nifedipine, a medicine used to treat HAPE. Nifedipine eases the pressure around your lungs and reduces the fluids that are oozing into them. It gives you some basic relief and enough time to descend to a lower altitude. You’ll see symptoms reducing within 30 minutes after administering the medicine. It is usually administered in 2 stages,10 mg first, wait for half an hour, and then another 10 mg. You should begin to see the effects within 30 minutes to an hour.

The rarest form of altitude sickness is High Altitude Cerebral Edema, HACE. HACE is as dangerous as HAPE because the altitude is now playing with your nervous system. HACE occurs when there’s an inflammation in your brain, and fluids accumulate in your brain. To cure HACE you need Dexamethasone also known as DEX. Dex is a medicine that helps reduce the inflammation caused by altitude sickness in your brain. It gives you almost immediate relief. This relief period is basically time for you to evacuate yourself to safety. Since Dex is also a steroid, it gives you a sudden burst of energy to get yourself out of there. It’s available in very small doses in India, around 0.5 mg. It is administered along with Diamox in doses of around 4 mg, depending on the severity of the case.


Allergic reactions to these medicines are rare but can occur in people with penicillin or sulfa allergies. You should consult with your physician before taking these medications. If you want to know more about the complete line of treatment please visit Indiahikes.

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