If you have symptoms of mild altitude sickness, you shouldn'tgo any higherfor at least 24 to 48 hours.
Most cases will improve during this time, but it may help if you:
Make sure you tell the people you're travelling with how you feel, even if your symptoms are mild. This will help them be more aware of signs of severe sickness, such as irrational behaviour, if you develop them.
If you havemild symptoms of altitude sickness that don't disappear over the course of 24 to 48 hours,the best thing to do is descend by at least 500m (about 1,600 feet).
Don't attempt toclimb again until your symptoms have completely disappeared. Aftertwo to threedays, your body will have acclimatised and your symptoms should disappear.
If you have severe symptoms or your symptoms are getting worse, descend immediately by as much height as possible. This is because severe altitude sickness can be fatal if not treated quickly. Seek immediate medical help when you reach a low altitude.
Increasing your oxygen intake with bottled oxygen or portable hyperbaric chambers (also known as Gamow or Certec bags) can help to temporarily improve some of the symptoms of altitude sickness.
A portable hyperbaric chamber is a bag you're zipped into, whichis then pumped full of air. After one to two hours of treatment, your symptoms should improve significantly. The effect of the treatment is equivalent to descending about 2,000m (6,500 feet).
However, while oxygen treatment or theuse of a hyperbaric chamber can relieve the symptoms of altitude sickness, it's not a replacement for descending to a lower altitude. You should always descend if you have severe or worsening symptoms, even if you've had oxygen treatment.
Painkillers, such as paracetamol or ibuprofen, can be used to treat mild headaches caused by altitude sickness.
If you're experiencing nausea or vomiting, a type of medication called an antiemetic may be useful. Promethazine is an antiemetic medicine often used by people with altitude sickness.
Research has shown that acetazolamide (Diamox) can reduce the severity of altitude sickness symptomsand can help prevent the condition.
Altitude sickness can change the chemical balance of your blood. It's thought that acetazolamide helps correct this chemical imbalance.
In the UK,acetazolamide isn't licensedfor treating or preventing altitude sickness.However, it may sometimes be considered for use "off-label" to help prevent altitude sickness in people with a history of the condition. Some people find these quite distressing, so doctors often suggest trying it at home for two days before travelling if you're likely to use it at altitude.
You should let your doctor know if you have an allergy to any medicines before acetazolamide is prescribed. Your doctor will also check your medical history to see if acetazolamide is suitable for you.
Nifedipine is often used to treathigh blood pressure (hypertension), but it can also be useful in treating high altitude pulmonary oedema. See complications of altitude sicknessfor more information.
This medication decreases the narrowing of the artery that supplies blood to the lungs, helping to reduce chest tightness and ease breathing. It's usually taken as a tablet atsix- to eight-hour intervals.
Nifedipine can cause a sudden drop in blood pressure, so it's importantnot toget up too quickly from a lying or sitting position if you take it.
Find out what to do if you have symptoms of altitude sickness, who's affected, and how you can prevent it.
Find out about the symptoms of mild and severe altitude sickness, which include headache, dizziness, nausea and vomiting, shortness of breath, and an increased heart rate.
Find out how altitude sickness should be treated, including descending to a lower altitude, oxygen treatment, and different types of medication.
Altitude sickness can cause potentially life-threatening conditions that affect the brain or lungs. Find out what to do if someone has severe symptoms of altitude sickness.
Find out how to prevent altitude sickness, including climbing slowly, particularly at altitudes of 2,500m or above. Ascending gradually will give your body time to adapt.
Jessica Mathur, a GP from London, was surprised when she became ill with altitude sickness during a holiday in Peru.