High Altitude Sickness

High Altitude Sickness (HAS) may happen while travelling to areas 2,500 to3,000 metres above sea level. The three different kinds of HAS are: 

• Acute mountain sickness (AMS)
• High altitude cerebral edema or HACE (swelling of the brain) 
• High altitude pulmonary edema or HAPE (build-up of fluid in the lungs)

The symptoms of High Altitude Sickness include: 

• Headache
• Feeling tired
• Lightheadedness
• Difficulty staying asleep or waking very often
• Nausea and/or vomiting
• Feeling confused and easily annoyed (for HACE)
• Problems with walking, body movement and balance (for HACE)
• Breathlessness when resting or with activity (for HAPE)
• Coughing out pink, foamy mucus (for HAPE)

What you can do to prevent High Altitude Sickness 

• The best way to prevent HAS is to allow your body time to acclimatise. Give your body time to adjust to the changes in air pressure by climbing up to higher altitudes slowly.   
• If you live less than 1,500 metres above sea level, avoid going up too quickly.
• If you plan to travel to more than 3,000 metres above sea level, do not climb more than 500 metres per day. Plan a day of rest for every 1,000 metres you climb.
• Climb high and sleep low. Hike to a higher altitude during the day and go back to a lower elevation to sleep at night. This will help you adjust to the altitude.
• If you plan to ski, hike, or climb, do not over-work your body during the first few days at high altitude. 
• Make sure that you drink enough water
• Avoid alcohol and sleeping pills, especially in the first two days.
• If you drink caffeine regularly, do not stop drinking it before or during your trip. Caffeine is safe at high altitudes, and stopping it suddenly can cause symptoms similar to HAS
• When at high altitude, eat meals that contain more starchy food

What you can do to relieve High Altitude Sickness 

• Treatment includes
  - Stop and rest
  - Go down to a lower altitude
  - Take medicine to relieve symptoms
• If your symptoms do not improve or worsen over 24 to 48 hours, go down to a lower altitude level where you feel better. Most people feel better after going down 500 to 1,000 metres 
• If needed, inhaled oxygen can reduce the symptoms of HAS. You can use oxygen for a period of time (e.g. one hour), only when you have symptoms, or while sleeping.
• You should not exercise or climb higher until you recover

When to see a Doctor 

AMS symptoms should usually improve within 24 to 48 hours as you get used to the higher altitude. If your symptoms worsen, you should go to lower altitudes and get help.

HACE and HAPE are dangerous and can cause death. If you have any symptoms of HACE or HAPE, you should go to lower altitudes and get medical help immediately.