AMS
Acute mountain sickness (AMS) is the most common type of altitude sickness. Symptoms usually develop within 6-12 hours of ascending, and can include:
- A throbbing headache that feels worse when you’re lay down
- Vomiting or nausea
- Weakness or fatigue
- Feeling dizzy or lightheaded
If you develop AMS symptoms: stop ascending. Over-the-counter painkillers might help ease headache symptoms, and if you’re not already taking them, acetazolamide tablets can help with the acclimatisation process. It’s important to rest, and remain at your current altitude, until symptoms ease off. If they start to get worse, you’ll need to begin descent and seek immediate medical attention.
HAPE
High-altitude pulmonary edema (HAPE) happens when fluid builds up in the lungs. Symptoms often start within the first 2-4 days when ascending to 2,500 metres or higher too quickly, and can include:
- Shortness of breath, even at rest
- A dry persistent cough (at first)
- Producing pink or frothy mucus (when condition becomes more severe)
- Extreme fatigue and decreased performance
- Chest tightness
- Rapid heartbeat
HAPE can be life threatening, so you’ll need to descend immediately, and seek medical help. Continuous oxygen can help ease symptoms, as can medication like dexamethasone.
HACE
High-Altitude Cerebral Edema (HACE) is the most severe, life-threatening form of altitude sickness and involves swelling of the brain. HACE symptoms can include:
- A severe loss of coordination
- Disorientation and confusion
- Feeling unusually lethargic
- Irrational behaviour, such as extreme mood swings
Like HAPE, the development of symptoms means you’ll need to descend rapidly. Oxygen and dexamethasone can also help HAPE symptoms, but returning to low altitudes urgently is the best way of getting the help you need.
