Altitude sickness
Some researchers think that AMS is more like a migraine headache, and indeed, AMS and migraine have some similarities, but they are not identical. This swelling causes pressure on the brain as it is squeezed against the skull, and the pressure might be the cause of the symptoms. Although everyone going to high altitude has slight brain swelling, it is worse in those who develop AMS. And because there is more blood in the brain, the brain is slightly swollen. Something about this vasodilation causes the headache. Current thinking is that hypoxia (low oxygen) in the air and blood causes the blood vessels of the brain to dilate in an attempt to get more oxygen.
Of course, AMS is due to low oxygen, but the steps between low oxygen and AMS are fuzzy. We have to admit that the exact cause of AMS is still not clear. Therefore, a person who has been doing well at altitude and then gets sick after two or three days needs to be evaluated for other conditions. Symptoms of AMS do NOT develop after 2 days of feeling well, unless one has moved to a higher altitude. Symptoms can occur as early as 2 hours after arrival to altitude, or be delayed for 24 hours or so. To meet the definition of AMS, other symptoms need to develop, such as loss of appetite, sometimes vomiting, weakness, dizziness, fatigue, and difficulty sleeping. AMS feels exactly like a bad hangover. One survey done at a Colorado ski resort at 9800 ft found that 60% of visitors developed a headache, the first sign of AMS, and also called high altitude headache. Most folks visiting these areas travel in one day from low to high altitude if an intermediate day is spent in Denver or a similar altitude, the incidence of AMS is much lower. In Colorado, between 15 and 40% of visitors sleeping at 8000 ft or higher get AMS, with the incidence the highest at the highest resorts.
*If symptoms develop do not go higher until symptoms disappear.AMS can afflict any visitor sleeping higher than 6000 feet. *Avoid sedatives, aspirin, and alcohol and do not over exert yourself *If you fly to a high altitude, get plenty of rest for a couple days after you arrive
*Having flexibility in your schedule so you can rest if symptoms develop is important. *Spend a night at a medium altitude before going to higher altitude Please seek travel health care advice to learn about prevention and treatment. There are prescriptions available to help prevent altitude sickness. Seek travel health advice 4-6 weeks prior to departure for more information. Altitude sickness can be very serious and you should be aware of the warning signs, and look out for other travellers in your group. It is important to be informed before you travel. Is there any prevention/treatment for altitude sickness? Common high-altitude destinations include: Pregnant Women should avoid high altitudes due to limitations on medical care and the possible effects on lowered oxygen in high altitudes on the fetus. There is very little data available to determine the effect of high altitude on young children. Sex, Age and fitness level do not appear to play a role in who will get altitude sickness. The largest concern for travellers to high altitudes is hypoxia (not being able to get enough oxygen) due to decreased air pressure, low humidity and cold. There is the possibility of severe and fatal symptoms as the sickness can affect your lungs and brain. Symptoms for altitude sickness vary from mild to severe and can include: severe headache, loss of appetite, nausea, vomiting, dizziness, fatigue and insomnia. Mild symptoms can resolve once the traveller has been acclimatized to the altitude. Travellers should not push past their limits. The best way to prevent altitude sickness is to ascend slowly to give your body time to adjust to the changes in oxygen. It is often described as feeling like a bad ”hangover”. Altitude sickness is commonly experienced when travellers go from a low altitude to higher altitude of 2100m (7,000 ft) above sea level.