Symptoms:

Symptoms range from mild to life-threatening, and can affect the nervous system, lungs, muscles, and heart.

In most cases, the symptoms are mild. Symptoms generally associated with mild to moderate acute mountain sickness include:

• Difficulty sleeping
• Dizziness or light-headedness
• Fatigue
• Headache
• Loss of appetite
• Nausea or vomiting
• Rapid pulse (heart rate)
• Shortness of breath with exertion

Symptoms generally associated with more severe acute mountain sickness include:

• Bluish discoloration of the skin (cyanosis)
• Chest tightness or congestion
• Confusion
• Cough
• Coughing up blood
• Decreased consciousness or withdrawal from social interaction
• Gray or pale complexion
• Inability to walk in a straight line, or to walk at all
• Shortness of breath at rest

Signs and tests:

Listening to the chest with a stethoscope (auscultation) reveals sounds called crackles (rales) in the lung, which may be a sign of fluid in the lungs.

A chest x-ray may be performed.