Altitude Sickness or Acute Mountain Sickness (AMS)

Altitude sickness, also known as acute mountain sickness (AMS), is a condition that occurs when people ascend to high altitudes too quickly without acclimatization. This condition is caused by a lack of oxygen at high altitudes, leading to various symptoms that can range from mild to life-threatening. In this response, we will discuss the case, pathophysiology, signs, symptoms, investigation, treatment, and advice related to altitude sickness.

Mr. John, a 35-year-old man, went on a hiking trip to the mountains. He had no prior experience with high-altitude environments. After reaching an altitude of 3000 meters, he began to experience symptoms of altitude sickness, including headache, nausea, dizziness, and fatigue.


At high altitudes, the air pressure and oxygen levels decrease, leading to a condition called hypoxia. This can cause various physiological changes in the body, such as increased heart rate, respiratory rate, and blood pressure. The body tries to compensate for the lack of oxygen by increasing the number of red blood cells, but this process takes time. If a person ascends too quickly, their body may not have enough time to adapt to the lower oxygen levels, leading to altitude sickness.

Signs and Symptoms

The signs and symptoms of altitude sickness can vary from person to person and can range from mild to severe. Some of the common symptoms include:

  • Headache
  • Nausea or vomiting
  • Dizziness or lightheadedness
  • Fatigue or weakness
  • Shortness of breath
  • Loss of appetite
  • Difficulty sleeping

In severe cases, altitude sickness can lead to high-altitude pulmonary edema (HAPE) or high-altitude cerebral edema (HACE), which are life-threatening conditions.


Diagnosing altitude sickness is usually based on the person’s symptoms and medical history. However, some investigations can help confirm the diagnosis, such as a physical exam, blood tests, or pulse oximetry.


The best treatment for altitude sickness is to descend to a lower altitude. If the symptoms are mild, resting and staying hydrated can help alleviate the symptoms. Over-the-counter medications such as ibuprofen can help relieve headache and other symptoms. In severe cases, oxygen therapy or medications such as acetazolamide or dexamethasone may be necessary.

Dos and Don’ts

  • Do ascend slowly, giving the body enough time to acclimatize to the lower oxygen levels.
  • Do stay hydrated by drinking plenty of fluids.
  • Do listen to your body and rest if you feel tired or sick.
  • Don’t ascend too quickly, especially if you have not been to high-altitude environments before.
  • Don’t drink alcohol or use sleeping pills, as they can make altitude sickness worse.
  • Don’t ignore the symptoms of altitude sickness, as they can lead to life-threatening conditions if left untreated.


Roach, R. C., Hackett, P. H., & Oelz, O. (Eds.). (2013). Hypoxia and mountain medicine: Proceedings of the 7th International Hypoxia Symposium, Lake Louise, Canada, 1993. Springer Science & Business Media.

Luks, A. M., McIntosh, S. E., & Grissom, C. K. (2019). Wilderness Medical Society consensus guidelines for the prevention and treatment of acute altitude illness. Wilderness & environmental medicine, 30(4S), S3-S18.

Limbic 365

Follow us

Don't be shy, get in touch. We love meeting interesting people and making new friends.