Altitude sickness
DEFINITION
Altitude sickness refers to a group of syndromes that result
from the combination of reduced air pressure and a lower
concentration of oxygen at high altitude.
from the combination of reduced air pressure and a lower
concentration of oxygen at high altitude.
DESCRIPTION
Altitude sickness can be classified into acute mountain
sickness (AMS), high altitude pulmonary oedema (HAPE) or high
altitude cerebral oedema (HACE). Physical fitness and climbing
experience don’t protect against any form of altitude
sickness.
sickness (AMS), high altitude pulmonary oedema (HAPE) or high
altitude cerebral oedema (HACE). Physical fitness and climbing
experience don’t protect against any form of altitude
sickness.
In most cases the symptoms are mild. In severe cases fluid
collects in the lungs (pulmonay oedema) causing extreme shortness
of breath, which further reduces how much oxygen a person gets.
Brain swelling may also occur (cerebral edema). This can cause
confusion, coma, and if untreated, can be fatal.
collects in the lungs (pulmonay oedema) causing extreme shortness
of breath, which further reduces how much oxygen a person gets.
Brain swelling may also occur (cerebral edema). This can cause
confusion, coma, and if untreated, can be fatal.
The chance of getting acute mountain sickness increases the
faster a person climbs into a high altitude. The severity of the
symptoms also depends on this factor, as well as how much the
person exerted him or herself. People who normally live at or near
sea level are more prone to acute mountain sickness.
faster a person climbs into a high altitude. The severity of the
symptoms also depends on this factor, as well as how much the
person exerted him or herself. People who normally live at or near
sea level are more prone to acute mountain sickness.
Approximately 20% of people will develop mild symptoms at
altitudes between 6,300 to 9,700 feet, but pulmonary and cerebral
oedema are extremely rare at these heights. However, above 14,000
feet, a majority of people will experience at least mild symptoms.
Some people who stay at this height can develop pulmonary or
cerebral edema.
altitudes between 6,300 to 9,700 feet, but pulmonary and cerebral
oedema are extremely rare at these heights. However, above 14,000
feet, a majority of people will experience at least mild symptoms.
Some people who stay at this height can develop pulmonary or
cerebral edema.
CAUSES
Altitude sickness may occur when the pressure of the
atmosphere decreases as the altitude increases, and the level of
oxygen in the air remains the same. As a person climbs upwards, the
air pressure drops, which results in less oxygen being forced into
the lungs with each breath. In an attempt to inhale more oxygen, a
person starts to breathe rapidly. The waste products produced by
this breathing causes swelling in the tissues of the body, which
can affect the lungs and brain and may even result in death. Excess
carbon dioxide is also exhaled during rapid breathing, which leads
to salt retention and accompanying fluid retention and swelling.
Blood pressure increases, which can cause blood clots and
haemorrhaging in the lungs and brain and behind the eyes in severe
cases.
atmosphere decreases as the altitude increases, and the level of
oxygen in the air remains the same. As a person climbs upwards, the
air pressure drops, which results in less oxygen being forced into
the lungs with each breath. In an attempt to inhale more oxygen, a
person starts to breathe rapidly. The waste products produced by
this breathing causes swelling in the tissues of the body, which
can affect the lungs and brain and may even result in death. Excess
carbon dioxide is also exhaled during rapid breathing, which leads
to salt retention and accompanying fluid retention and swelling.
Blood pressure increases, which can cause blood clots and
haemorrhaging in the lungs and brain and behind the eyes in severe
cases.
SIGNS AND SYMPTOMS
- Headache
- Fatigue
- Nausea
- Dizziness
- Shortness of breath or difficulty breathing
- Sleep disturbance
- Appetite loss
- Altered mood
- Impaired performance
- Rapid, forceful heartbeat
TREATMENT OPTIONS
- If you experience any symptoms of altitude sickness,
immediately descend to a lower altitude. Even descending as little
as 300 metres can help. - Avoid strenuous exercise after altitude sickness, however,
light exercise is recommended.
DIET HINTS
- Drink more water than usual, as dehydration is a common symptom
associated with climbing to higher altitudes. Water loss is greatly
increased by rapidly breathing dry air, which becomes thinner at
high altitudes. Consider a fluid replacement or Oral Rehydration
Solution that can be carried with you and added to water to help
replace fluids. - Avoid alcohol, sleeping pills or narcotics, which often worsen
the effects. - Eat frequent, small meals of carbohydrates (eg. fruits, jams,
starches), which are easy to digest and can improve a person’s
tolerance to altitude. Include low-fat and low-salt foods to help
prevent the onset of altitude sickness. This is especially
important in the first few days of being at high altitudes. - Carry light, healthy snacks which provide quick energy (e.g.,
dried fruits, nuts, sandwiches, fruit bars and biscuits). - Eat light foods such as fruits, vegetables, salads, and
starches such as bread, rice pasta and potatoes for easy digestion,
especially during the first few days of adjusting to high
altitudes.
PREVENTION
- The best way to avoid altitude sickness is to ascend slowly at
a rate of 300 metres (1000 feet) per day. - Allow 2 days to acclimatise to a high altitude before doing any
strenuous exercise such as rock climbing or hiking. - Ask your doctor for medication that can help prevent altitude
sickness.
SUPPLEMENTS AND HERBS
- Vitamin E boosts blood flow to the tissues and may help prevent
damage to tissues caused by insufficient oxygen supply. - The herb ginkgo biloba boosts blood flow through the small
blood vessels of the body thereby increasing oxygen supply to the
tissues.
