Acute Mountain Sickness (AMS), AKA altitude sickness

Parts of your trip go above 2800 metres where it is common for travellers to experience some adverse effects on your health due to the altitude. It even happened to Sir Edmund Hillary!

While our leaders have basic first aid training and are aware of the closest medical facilities, it is very important that you make yourself aware of the cause and effects of travelling at altitude, monitor your health and seek assistance accordingly.

Please read this document carefully and utilise the table on the back on a daily basis to record your own perspective of your general health and any symptoms you may be experiencing.

Please note this document is assembled from feedback from past travellers experiences information provided through the writings of renowned altitude expert Dr Jim Duff as well as from the 'High Altitude Medicine Handbook'.

The following is for information purposes only and is in no way intended to replace the advice of a trained medical professional. As such Intrepid is unable to accept responsibility for any loss, injury or inconvenience sustained by any person, caused by errors and omissions, or as a result of the advice and information given here. For further info please read Travel at High Altitude.

Before your trip

Some pre-existing medical conditions are known to severely worsen at high altitude and be difficult to adequately treat on the ground, leading to more serious consequences. It is imperative that you discuss your pre-existing medical condition/s with your doctor. We understand certain medications are reported to aid acclimatizing to high altitude. Please discuss these options with your doctor.

During your trip

While our leaders have basic first aid training and are aware of the closest medical facilities, it is very important that you are aware of the cause and effects of travelling at altitude, monitor your health and seek assistance accordingly.

What is it?

Altitude sickness is the reaction of the body adjusting to decreasing amounts of oxygen. Normally, the higher the altitude, the less oxygen available for the body to carry on normal functions.

Altitude sickness most commonly occurs from above 2,800 metres (9,200 ft) but this is different for everyone - there is simply no way of knowing your own susceptibility prior to being at altitude thus it is vital you monitor your own health.

Symptoms may be mild and subside/go away after a day’s rest, or if it is ignored it could lead to death.

Symptoms of altitude sickness

Symptoms can appear within 1-2 hours although most often appear 6-10 hours after ascent and generally subside in 1-2 days as the body adjusts to altitude. They may reappear as you continue to go higher.

Symptoms usually occur gradually & can be one or a combination of the following:

  • Headache

  • Loss of appetite

  • Disturbed sleep or drowsiness

  • Irritability

  • Fatigue

  • Nausea/vomiting

  • Dizziness

  • Swelling of hands, feet & face

If the body is unable to adjust to altitude these symptoms will persist and, if they are left untreated, altitude sickness may progress to High Altitude Cerebral Edema (HACE) or High Altitude Pulmonary Edema (HAPE). Both can be fatal if ignored.

Symptoms of HAPE (fluid on the lungs)

  • Breathlessness
  • A dry cough, developing to a wet one with blood-tinged discharge or saliva.

  • Tightness in the chest & blueness/darkness of face, lips & tongue

  • Low fever up to 38°C

  • Severe fatigue, progressing to coma

HAPE can occasionally develop without the usual symptoms of AMS - a telltale sign is breathing does not return to normal when at rest, it remains shallow, rapid and panting even after an extended period of inactivity, often accompanied by a cough.

Symptoms of HACE (fluid on the brain)

  • Severe headache symptoms not relieved by painkillers or lying down
  • Confusion, disorientation and drowsiness

  • Nausea/vomiting

  • Loss of balance or coordination

  • Blurred or double vision/retinal haemorrhage

How do I avoid altitude sickness?

Certain medical conditions (such as respiratory disease) or medications (such as sleeping pills) can increase the risk of altitude sickness - it is important that you inform your leader of any medical conditions or medications before ascending to altitude.

You can help your body to acclimatise and avoid altitude sickness by:

  • Drinking plenty of water - at least 4 litres per day on top of other forms of fluids such as tea or soups

  • Avoiding alcohol, tobacco and substances that can interfere with good delivery of oxygen to the body or cause dehydration.

  • Eating small, frequent meals high in carbohydrates.

  • Taking it easy or have a regular break. Walk at a slower pace than you would at sea level and avoid over-exertion

Treatment

Most travellers can successfully acclimatise by following the previously mentioned guidelines. However, there are instances where medical treatment is required.

Ultimately, the best treatment for acute altitude sickness is to descend to a lower altitude.

There may be times when your leader makes the decision that you or a member of your group is at risk of serious altitude sickness and, for safety, insists that you cannot ascend further - please respect that they are within their rights to do so and are making that decision in the best interests of your health and well-being.

We recommend you keep track of altitude-related symptoms you may experience by completing the chart below from the first day you experience any altitude sickness symptoms.

If you are experiencing any altitude sickness symptoms, we encourage you to discuss them with your leader immediately so you can follow your acclimatisation progress. However, should you rate the severity of any symptoms at 7 or more, or the symptoms continue/worsen after the initial 1-2 days, please inform your leader without delay so that we can seek the advice of a trained medical professional if necessary.

Everyone will have a different perception of the severity of their symptoms; the key is to assess whether your symptoms are improving or worsening personally.

A rough guide would be:

1 = Very minor symptoms that are causing no discomfort
5 = Moderate discomfort
10 = Extreme discomfort