Altitude Sickness

Altitude sickness often known as acute mountain sickness (A.M.S.) in general may occur when people ascend too quickly normally at altitudes of over 3000 m. We ensure minimal risk by building in rest days into our trekking itineraries. Most people will feel some effect of altitude, shortness of breath, and possibly light-headed, this is fairly common. Acute mountain sickness is very different and normally involves a severe headache, sickness, and loss of awareness. In almost every potential case there are enough warning signs to take appropriate action. Basically, there are three stages of altitude sickness and symptoms.

Normal AMS Symptoms

Should expect but not worry.
Following are the normal altitude symptoms that you should expect but not worry about. Every trekker will experience some or all of these, no matter how slowly they ascend.
Periods of sleeplessness

  • Need more sleep than normal (often 10 hours or more)
  • Occasional loss of appetite
  • Vivid, wild dreams especially at around 2500-3800 meters in altitude
  • Periodic breathing
  • The need to rest/catch your breath frequently while trekking, especially above 3500 meters
  • Runny nose
  • Increasing urination while moving to/at higher altitudes (a good sign) Dizziness.


Any trekkers in the high valleys of the Himalayas get mild AMS and admit or acknowledge that they are having symptoms. You need to have only one of the following symptoms to be getting altitude sickness.

  • Mild headache.
  • Nausea Dizziness
  • Weakness
  • Sleeplessness
  • Dry Raspy cough
  • Fatigue/Tired
  • Loss of apatite
  • Runny nose
  • Hard to breath

What to do if a mild symptom doesn’t go away?

  • If you find mild symptoms developing while walking, stop and relax (with your head out of the sun) and drink some fluids. Dink frequently.
  • If mild symptoms develop while walking, stop having rest, drink some fluids and take 125-250mg of Diamox. Diamox generally takes one to four hours to begin alleviating symptoms. Drink more water and consider staying close by.
  • If symptoms develop in the evening, take 125-250mg Diamox and drink plenty of fluids again. If symptoms partially go away but are still annoying it is safe to take another 250mg of Diamox 6-8 hours later.
  • If mild symptoms continue getting worse then descent for a few hours may be more beneficial than staying at the same altitude. Going higher will definitely make it worse. You trek to enjoy not feeling sick.


  • Persistent, severe headache
  • Persistent vomiting
  • Ataxia (loss of coordination, an inability to walk in a straight line, making the sufferer look drunk)
  • Losing consciousness (inability to stay awake or understand instructions)
  • Mental confusion or hallucinations
  • Liquid sounds in the lungs
  • Very persistent, sometimes watery, cough
  • Difficulty breathing Rapid breathing or feeling breathless at rest
  • Coughing clear fluid, pink phlegm, or blood (a very bad sign)
  • Severe lethargy/fatigue
  • Marked blueness of face and lips
  • High resting heartbeat (over 130 beats per minute)
  • Mild symptoms rapidly getting worse

Dangerous cases of AMS:

High Altitude Cerebral Edema (HACE) This is a build-up of fluid around the brain. In cases the first five symptoms on the mild and severe lists previously. Coma from HACE can lead to unconsciousness is death within 12 hours from the onset of symptoms, but normally takes 1-2 days to develop. At the first sign of ataxia begin treatment with medication, oxygen, and descent. Usually, 4 to 8mg of dexamethasone is given as a first dose, then 4mg every six hours, Diamox every 12 hours, and 2-4 liters/minute of oxygen. The descent is necessary but a PAC (portable altitude chamber) bag will often be used first if available. 

High Altitude Cerebral Edema(HACE)

High-altitude Cerebral Edema (HACE) is a medical condition in which the brain swells with fluid because of the physiological effects of traveling to a high altitude. It generally appears in patients who have Altitude Mountain Sickness and involves disorientation, lethargy, and nausea among other symptoms. It occurs when the body fails to acclimatize while ascending to a high altitude.

High Altitude Pulmonary Edema (HAPE)

This is an accumulation of fluid in the lungs and is very serious. It is responsible for all the other mild and serious symptoms and it is often accompanied by a mild fever. By far the treatment is oxygen at 4 liters a minute but using PAC (portable altitude chamber) bag treatment is a good substitute. If there is no PAC bag or oxygen then descent will be life-saving. HAPE can lead to unconsciousness are death very quickly.

Prevention of Acute Mountain Sickness (AMS)

  • Allow sufficient time for acclimatization (After 3000 meters)
  • Don’t make rapid Ascent. Don’t go too far too fast
  • No Alcohol, Sleeping pills, and Smoking
  • Drink more fluid 3-4 Liters a day, clean water-boiled or treated /tea/coffee/soup/juice, etc.
  • Climb high and sleep low
  • Do not trek/travel alone, take a guide/porter
  • Follow the advice from your guide, hotel, local, guide book
  • Descent if mild symptoms rapidly get worse.
  • Never leave or descend sick person along.
  • Avoid getting cold.
  • Take an easy and comfortable trekking route even if it is longer.

First Aid Kit

This is the basic list to cover the more common ailments that afflict trekkers. The climbing group, expeditions, and trekkers going to isolated areas will need a more comprehensive kit.

  • Bandage for sprains
  • Plasters/Band-aids
  • Iodine or water filter (optional)
  • Moleskin/Second skin - for blisters
  • Antiseptic ointment for cuts
  • Anti-bacterial throat lozenges (with antiseptic)
  • Aspirin/Paracetamol - general painkiller
  • Oral rehydration salts Broad-spectrum antibiotic (norfloxacin or ciprofloxacin)
  • Anti-diarrhoea medication (antibiotic)
  • Diarrhea stopper (Imodium - optional)
  • Antibiotic for Guardia or similar microbe or bacteria
  • Diamox 250/500mg (for altitude sickness - can be bought in Kathmandu)
  • Sterile Syringe set (anti-AIDS precaution)
  • Gel hand cleaner