Mountain safety 

What is acute mountain sickness?

Hikers who travel to high altitudes can sometimes experience Acute Mountain Sickness (AMS). Besides AMS, there are also the more severe variants High Altitude Cerebral Edema (HACE) and High Altitude Pulmonary Edema (HAPE).

Please note before reading the given information: The information in this section, as with the whole website, is provided as an information resource only, and is not to be used or relied on for any diagnostic or treatment purposes. The information should not be used as a substitute for professional diagnosis and treatment. Research in this area is always progressing which may mean some of this information is out of date. It is your responsibility to seek the latest information should you be going to high altitudes.

AMS typically occurs from about 8,000 feet, or 2,400 meters, above sea level. Most of the time, this sickness is mild and heals quickly. In rare cases, altitude sickness can become severe and cause complications with the lungs or brain.


What causes AMS?

The higher altitudes, such as the Mt. Kilimanjaro summit has lower levels of oxygen and decreased air pressure. When you hike up a mountain with higher altitudes, your body might not have enough time to adjust to these higher altitudes. This can result in acute mountain sickness. Your level of exertion also plays a role. Pushing yourself to quickly hike up a mountain, for

example, may cause acute mountain sickness.


What are the symptoms of AMS?

The symptoms of AMS generally appear within hours of moving to higher altitudes. They vary depending on the severity of your condition. When you start to experience mild symptoms of AMS, it is very important to let the mountain crew of Moana Tanzania immediately. They will determine if it is necessary to adjust the schedule to relieve your symptoms.

Mild symptoms of AMS:

  • Headache
  • Fatigue
  • Nausea and vomiting
  • Dizziness
  • Disturbed sleep / insomnia
  • Loss of appetite
  • Muscle aches
  • Irritability
  • Swelling of hands, feet and/or face
  • Rapid heartbeat
  • Shortness of breath with physical exertion


Moderate symptoms of AMS:

A clear sign that you are experiencing moderate altitude sickness symptoms is when one or all of the mild symptoms start getting worse to a degree that becomes debilitating. It is very important that people who experience moderate symptoms of AMS, descend immediately for at least 1000 feet (300m), but more if necessary, and that they remain at a lower altitude until the symptoms subside. Once the symptoms have disappeared you have acclimatized and you can ascend again.


The symptoms include:

  • Very fatigued and weak
  • Severe headaches that cannot be relieved by medicine
  • Inability to walk or lack of balance (ataxia)
  • Nausea that mostly leads to vomiting
  • Shortness of breath


Severe symptoms of AMS:

Severe cases of AMS can cause more intense symptoms and affect your heart, lungs, muscles, and nervous system. Severe AMS can lead to life-threatening complications (HAPE and HACE). Ascending with severe symptoms of AMS is extremely dangerous and should never occur.

The symptoms include:

  • Coughing
  • Social withdrawal
  • Loss of mental capacities and hallucination
  • Chest congestion
  • Shortness of breath
  • Inability to walk or lack of balance (ataxia)
  • Pale complexion and skin discoloration


High Altitude Cerebral Edema (HACE)

HACE occurs due to swelling of the brain tissue from fluid buildup in the cranium. The condition is very rare, but it almost always occurs when ascending too high too fast or because someone stayed at a high altitude for too long. The condition, HACE, is associated with AMS. It is a life-threatening condition and should be treated immediately. HACE cannot be treated without immediate evacuation to a medical facility.

The symptoms include:

  • Disorientation, confusion, hallucinations, talking nonsense
  • Loss of consciousness
  • Loss of coordination (ataxia)
  • Memory loss
  • Coma
  • Irrational behavior

High Altitude Pulmonary Edema (HAPE)

HAPE occurs because of fluid build-up in the lungs. The condition is associated with AMS, but HAPE can also occur if the hiker did not experience signs of AMS. The condition is very rare, but it almost always occurs when ascending too high too fast. It is a life-threatening condition and should be treated immediately. HAPE cannot be treated without immediate evacuation to a medical facility.

The symptoms include:

  • Abnormal lung sounds
  • Very short of breath, even when the hiker is resting
  • Coughing up blood or mucus
  • Very tight feeling of the chest
  • The feeling of suffocation
  • Lips turning blue
  • Confusion, lack of coordination, hallucination

How is AMS treated?

Treatment for AMS varies depending on its severity. You might be able to avoid complications by simply returning to a lower altitude. Hospitalization is necessary if your doctor determines that you have brain swelling or fluid in your lungs (HACE or HAPE). You may receive oxygen if you have breathing issues.

Medications for altitude sickness include:

  • Acetazolamide (also known as: Diamox), to correct breathing problems
  • blood pressure medicine
  • lung inhalers
  • dexamethasone, to decrease brain swelling
  • aspirin, for headache relief

Other treatments

  • returning to a lower altitude
  • reducing your activity level
  • resting for at least a day before moving to a higher altitude
  • hydrating with water

How can I prevent acute altitude sickness?

You can take some important preventive steps to reduce your chances of acute mountain sickness:

  • Choose the mountain itinerary/route wisely. If you take a longer route and more days on the mountain, your body will acclimatize better and this decreases the chance of AMS.
  • Don’t hike too fast. You don’t want to tire your body out.
  • Stay hydrated. It is advised to drink at least 3 liters (preferably 4 liters) of water each day.
  • Keep eating, particularly carbohydrates, even if you don’t feel hungry.
  • Get a physical examination at a doctor to make sure you have no serious health issues.
  • Review the symptoms of mountain sickness so you can recognize and treat them quickly if they occur.
  • Consider taking medication (such as diamox) with you that can help to prevent AMS

Medication (Diamox):

Acetazolamide, or Diamox, is a drug that has been proved to be effective at mitigating altitude sickness. It is important to note that Diamox is a prophylactic (preventative medicine), and does not cure the symptoms of AMS. Once the symptoms of AMS have started, the only way to cure them is to descend. Diamox should therefore never be used to continue your ascend to the summit while already experiencing symptoms of AMS.

Diamox can only be prescribed by a doctor. Therefore it is important to consult your doctor first and to see if Diamox is a suitable solution for you. We recommend taking Diamox for 2-3 days 2 weeks before departure to test whether you experience any side effects. What are the (long-term) consequences of mild symptoms of AMS? Most people recover from mild symptoms of AMS very quickly after descending to a lower altitude. Symptoms typically subside within hours, but may last up to two days. If you experience mild symptoms of AMS for longer than two days after your descent, it is wise to consult a doctor.

Daily health checks while on the mountain

The guides of Moana Tanzania are experienced in identifying altitude sicknesses and will do health checks with the hikers every day while on the mountain. The pulse oximeter is part of the daily health checks. The pulse oximeter test is a noninvasive test that measures the oxygen saturation level of your blood. It can rapidly detect even small changes in oxygen levels. These levels show how efficiently blood is carrying oxygen to the extremities furthest from your heart, including your arms and legs.