Altitude sickness, also known as acute mountain sickness or AMS, is caused by the lack of oxygen into the body.

AMS typically occurs at around 8,000 feet and above. As a climber ascends to areas with lower pressure and thinner air, the amount of oxygen in each breath decreases, leaving blood and body tissue saturation without enough oxygen to properly function.  AMS affects all climbers, although all have varying degrees of severity. Symptoms of AMS include headache, nausea, dizziness and insomnia. Although not usually serious, these symptoms can be early signs of HAPE or HACE. Any climber who suffers with vomiting and a severe splitting headache, should make immediate plans for descent to a lower altitude.

 

HAPE is a potentially fatal condition that can follow AMS, but can also appear in climbers without altitude sickness. The cause of HAPE is due to low oxygen levels, resulting in the narrowing of the pulmonary artery in the heart, releasing blood near the alveoli (tiny branches of the lungs). If ignored, blood can flow into the alveoli inducing coughing and blood-soaked phlegm.

Classic symptoms include, chest pain, wheezing, shortness of breath, even at rest, and coughing. Another sign of advanced HAPE is known as the "death rattle", which occurs when fluid is in the lungs and rattles with every breath taken.

HACE is extremely severe and often fatal if ignored by the climber. HACE is the swelling of the brain tissue through fluid leakage from blood vessels.

HACE occurs when climbers ignore the warning signs of AMS and continue to climb to a higher altitude. Symptoms are generally those experienced with AMS with other signs including, fatigue, confusion, hallucinations and disorientation; with the final symptom being a coma.  

Hypothermia
Once body temperature falls below 35C/95F, shivering starts and the body works to maintain your core temperature where vital organs are located. This is achieved by drawing blood circulation away from your extremities such as arms and legs. The symptoms of hypothermia are clumsiness, impaired judgement, slurred speech, weakness and progressive mental impairment. If left without treatment this will lead to heart dysfunction, loss of consciousness and ultimately death.

Frostbite
Frostbite occurs on a climber's extremities. So hands, feet, ears and nose, if left exposed to freezing temperatures for a prolonged period of time, will become white, with total loss of sensation around the tissue area. Treatment for frostbite is to submerse the effected area into cold water and slowly heat the water until the area is thawed. If left untreated, the frostbitten areas turn black, blister and then fall off. We don't want frosbite then!!!!

Fainting
Known as high altitude syncope; this is a harmless but common problem among climbers where they suddenly faint. This occurs predominantly after their arrival at altitude but is easily remedied by putting them into a reclined position, with their legs raised, to get blood back into the brain.

Sleep Hypoxia - No chance of that happening...
As the body adjusts to such high altitudes, climbers can experience sleep disturbance caused by the lack of oxygen, resulting in irregular breathing patterns at night.

Snow Blindness
Snow blindness occurs when climbers remove their glasses. The sun then burns the cornea of the eye causing an increased exposure to ultraviolet radiation at altitude. The effects are worsened due to the snow's reflective abilities which increases ultraviolet light exposure by an additional 80%.

Sunburn - This is not Spain you know..
Climbers should wear a minimum suncream factor of 30 when climbing at altitude, as sunburn poses a real danger in such an exposed environment. Sunburn can even occur in the nostrils and in the roof of the mouth, as the climbers breathe more heavily, due to the reflection of sunlight.

Weight Loss - Forget Weight Watchers
Climbing at altitude increases metabolism and reduces appetite, but also the intestines lose their effectiveness at absorbing fats, which results in significant weight loss.

Descent
Descent to lower altitude is probably the best treatment if suffering from any altitude related illness. Recovery from symptoms of AMS can be immediate, with no clear indication of the height to which they should descend, to show improvement.

Dexamethasone
This is a drug used to treat HACE; a potential life saver. Commonly referred to as DEX,  it decreases swelling of the brain and reduces pressure on the skull. DEX is used to give the climber more time if descent is going to be slow or problematic. This should not be seen as a cure, as with all altitude related illnesses, descending as soon and as quickly as possible is the key.

Nifidepine
This is normally prescribed to treat high blood pressure. It is also used to suppress narrowing of the pulmonary artery, allowing more oxygen to circulate around the body. Nifidepine is used to treat climbers suffering with HAPE.

Diamox (Acetazolamide)
This drug is most commonly used for both preventing and treating AMS. It increases the alkali content of urine, causing the blood to become more acidic, which in turn improves ventilation.

Portable Hyperbaric Bag or Gamow Bag
This is an airtight inflatable bag, big enough for a single climber to fit inside. It is operated by foot pump and used to treat severe cases of HACE or HAPE, where immediate descent is compromised. With the climber sealed inside the bag, the bag is then inflated to simulate a higher air pressure or lower altitude by as much as 500 metres. Use of this piece of equipment can see climber's symptoms reduce within 1 hour. Descent to a lower altitude is still essential, as this is a temporary treatment.

Oxygen
At the risk of stating the obvious, breathing additional oxygen is probably the most effective treatment for AMS... Right, we are staying at base camp then!!!!