Altitude sickness is common in climbers that ascend to 2,500 metres above sea level, or higher, too quickly. The decrease in atmospheric pressure makes breathing difficult as you are unable to take in as much oxygen as normal. Some of the mild symptoms of altitude sickness are headache, nausea, dizziness & exhaustion. In some cases these symptoms can turn into serious conditions, and may require immediate medical attention, some of the symptoms to look out for are bubbling sounds on the chest, vision disturbance, palpitations, fatigue, swelling behind the eyes.There are a number of measures that you can take to help avoid symptoms of altitude sickness, the most common way is to climb slowly so your body can properly acclimatise to heights of 2,500m or more. Normally your body will need 24-48 hours to adjust, if symptoms have calmed after this time you can start to ascend. It is important to remember that once you are above 3,000 metres, not to increase altitude of more than 300-500m per night. Altitude sickness is fairly common in mountineers and skiers, as most ski resorts are around this height. Travelpharm offer Acetazolamide which is taken twice a day. You should begin taking the medication two days before you start to ascend. Continue taking it while you are ascending and for at least two days after you have reached your highest altitude. For further information regarding altitude sickness, see our Altitude Sickness information page.