High Altitude Sickness

High Altitude Sickness

High Altitude Sickness (Acute Mountain Sickness - AMS) is a condition that occurs when your body doesn't adapt well to lower oxygen levels at elevations above 2,500 meters (8,200 feet). It commonly affects trekkers, climbers, and travelers in mountainous regions like the Himalayas, Andes, or Rockies.

Types of Altitude Sickness

1. Acute Mountain Sickness (AMS) – Mild, most common form
2. High Altitude Pulmonary Edema (HAPE) – Fluid in the lungs; potentially fatal
3. High Altitude Cerebral Edema (HACE) – Swelling in the brain; a medical emergency

Common Symptoms of AMS

- Headache
- Nausea or vomiting
- Dizziness or lightheadedness
- Fatigue
- Loss of appetite
- Trouble sleeping
- Shortness of breath (especially with exertion)

Causes

- Ascending too quickly
- Not allowing the body enough time to acclimatize
- Physical exertion at high altitude

Prevention

- Ascend gradually (no more than 300–500m per day above 3,000m)
- Take rest days for acclimatization
- Stay hydrated and avoid alcohol
- Consider acclimatization medications like acetazolamide (Diamox)
- 'Climb high, sleep low' strategy

Treatment

- Descend to a lower altitude immediately if symptoms worsen
- Rest and hydration
- Oxygen therapy (if available)
- Medications (Diamox for AMS, nifedipine for HAPE, dexamethasone for HACE)

When to Seek Help

- If symptoms become severe (confusion, difficulty walking, chest tightness, breathlessness at rest), descend immediately and seek medical help, it could be HAPE or HACE, both of which can be fatal if untreated.
Proper acclimatization and awareness are key to staying safe at high altitude.

High Altitude Pulmonary Edema (HAPE)

HAPE is a life-threatening condition caused by fluid accumulation in the lungs due to rapid ascent to high altitudes, typically above 2,500–3,000 meters (8,200–9,800 ft).

Symptoms of HAPE

- Persistent dry cough that may produce frothy or pink sputum
- Shortness of breath at rest
- Chest tightness or congestion
- Extreme fatigue and weakness
- Rapid heartbeat (tachycardia)
- Cyanosis (bluish lips or fingernails)
- Crackling sounds in the lungs (on auscultation)
- Difficulty walking in a straight line
- Confusion or irrational behavior (if combined with HACE)

Symptoms typically worsen at night or with exertion.

Prevention

- Ascend slowly: No more than 300–500 m per day above 3,000 m
- Take rest/acclimatization days
- Avoid overexertion
- Stay hydrated, avoid alcohol and sleeping pills
- Use prophylactic medications (only under medical advice):
- Nifedipine (lowers pulmonary pressure)
- Salmeterol inhalers or Acetazolamide (for some cases)

Treatment

- Immediate descent (at least 500–1,000 m)
- Administer oxygen (if available)
- Keep the patient warm and rested
- Medications:
  - Nifedipine (primary drug to reduce pulmonary pressure)
- Oxygen therapy or portable hyperbaric chamber if descent isn’t possible
- Dexamethasone may be used if HACE is also suspected

Important

HAPE can progress rapidly and be fatal within hours if untreated. Never ignore early symptoms, and always descend if in doubt.

High Altitude Cerebral Edema (HACE)

HACE is a severe and life-threatening form of altitude sickness caused by swelling of the brain due to low oxygen levels at high altitude, usually above 3,500 meters (11,500 ft).

Symptoms of HACE

- Severe headache (unrelieved by painkillers)
- Loss of coordination (ataxia): stumbling, inability to walk straight
- Confusion, disorientation, or hallucinations
- Slurred speech
- Extreme fatigue or weakness
- Visual disturbances
- Irrational behavior or mood changes
- Loss of consciousness (in advanced stages)
- May be preceded by symptoms of AMS

Prevention of HACE

- Ascend gradually (not more than 300–500 m per day above 3,000 m)
- Include rest/acclimatization days
- Avoid alcohol, sedatives, and excess exertion
- Use Acetazolamide (Diamox) preventively (under medical advice)
- Follow the “climb high, sleep low” principle

Treatment of HACE

- Immediate descent: at least 500–1,000 meters, the most crucial step
- Administer oxygen if available
- Use portable hyperbaric chamber if descent isn't possible
- Dexamethasone: 8 mg initially, then 4 mg every 6 hours (oral or injectable)
- Keep the patient warm, rested, and avoid physical activity
- Monitor for symptoms of HAPE, which may occur together

Emergency Note

HACE is a medical emergency. Without descent and treatment, it can lead to coma or death within hours. If any signs of confusion, ataxia, or behavior change appear, assume HACE and descend immediately.