Ever been struck by a bout of nausea on a trek in the mountains? Learn about high altitude sickness and how to cope with it.
What is high altitude?
High altitude in mountaineering refers to heights over 5,000 m (16,000 ft). At 5,000 m, the quantity of oxygen in the air is a quarter of what it is at sea level. As altitude increases, the oxygen content of the air decreases. The body may feel the effect of thinning air from about 10,000 ft (3,048 m) onwards. Above 8,000 m is known as the Death Zone. No one can live there and mountaineers use bottled oxygen at these heights.
How does it affect us?
The body needs oxygen. Oxygen from the air goes to the lungs and is absorbed into RBCs (red blood corpuscles) that transport it to the rest of the body. As we climb higher, the amount of oxygen the body takes in with each breath lessens. The body compensates by making more RBCs. When a huge number of RBCs absorb oxygen, the body gets the oxygen it needs.
When our body cells do not get adequate oxygen, they die.
Mountaineers who climb the highest peaks without bottled oxygen lose brain cells.
Chances of frostbite increase.
Three illnesses can strike at high altitude
Mountain sickness is induced by slow acclimatisation and causes headache, nausea, inability to eat, vomiting, and face swelling.
is when fluid fills the lungs. It is recognised by coughing pink or blood-specked sputum and noisy breathing.
occurs when fluid fills the brain. Woolly-headedness, headaches, and disorientation are signs of cerebral oedema.
Gain height slowly. When we climb, the body registers the decrease in the oxygen and starts making RBCs. The body needs to get adequate time to make enough RBCs. This slow climbing is called acclimatisation.
Follow the 'climb high, sleep low' rule. Climb to a higher spot in the mountain, and then return to camp to sleep. The exposure to the lower oxygen content triggers RBC manufacture. Next day, you'll wake up prepared to climb.
To make RBCs, the body needs iron and water. Eat well and hydrate.
Everybody has their own rate of acclimatisation. Climb at a your own speed.
Travel with a buddy. Watch out for early signs of illness in each other. Cerebral oedema is tougher to detect than pulmonary oedema but a familiar partner will know when you're not placing your feet normally.
Sick? here's what to do
Lose height immediately. There is no treatment for oedema. Only descent to a place with more oxygen helps.
For very high altitude treks, you could use a inflatable altitude compression chamber. The ill person is put in the bag, which simulates the air of a lower altitude. This buys time for evacuation.