What is altitude sickness?
Peru Altitude sickness occurs when you cannot get enough oxygen from the air at high altitudes. This causes symptoms such as a headache, loss of appetite, and trouble sleeping.

When do you get altitude sickness?
It happens most often when people who are not used to high altitudes go quickly from lower altitudes to 8000 ft (2438 m) or higher.
Mild altitude sickness is common. Experts do not know who will get it and who will not. Neither your fitness level nor being male or female plays a role in whether you get altitude sickness.

Why should I be very careful about altitude sickness?
Altitude sickness can be dangerous. It is smart to take special care if you go high-altitude hiking or camping (like in the Andes) or have plans for a vacation or trek in high-altitude countries like Peru, Bolivia, or Nepal.

What causes altitude sickness?
Air is “thinner” at high altitudes. When you go too high too fast, your body cannot get as much oxygen as it needs. So you need to breathe faster. This causes a headache and other symptoms of altitude sickness. As your body gets used to the altitude, the symptoms go away.

What are the symptoms?
The symptoms of altitude sickness include:
• A light headache
• Loss of appetite, nausea, or vomiting
• Fatigue or weakness
• Dizziness or light-headedness
• Difficulty sleeping
Your symptoms may be mild to severe. They may not start until a day after you have been at a high altitude. Many people say altitude sickness feels like having a hangover.
If you are going on a high-altitude trek, learn about altitude sickness, its symptoms, and how to treat it. Look out for other people in your group.

How is it treated?
The best treatment for altitude sickness is to go to a lower altitude. But if you have mild symptoms, you may be able to stay at that altitude and let your body get used to it. Symptoms often occur if you have just arrived at a mountain resort from a lower altitude.
You may also be able to use oxygen or a specially designed pressure chamber to treat altitude sickness.
If you stay at a high altitude, rest. You can explore the area but take it easy. Limit any walking or activity. Drink plenty of water, but do not drink alcohol. Do not go to a higher altitude until your symptoms go away. This may take from 12 hours to 3 or 4 days.
A doctor can give you acetazolamide (Diamox). This speeds up how fast your body gets used to the higher altitude. Nifedipine (Procardia) and dexamethasone are also used for altitude sickness. You may also be able to use oxygen or a specially designed pressure chamber to treat altitude sickness.
Go to a lower altitude if your symptoms are moderate to severe, they get worse, or medicine or oxygen treatment does not help. Go down at least 1500 ft (457 m). Go to a lower altitude as fast as you can or get emergency help if someone with you has severe symptoms such as being confused or not being able to walk straight. Go with the person. Never let someone with severe altitude sickness go down alone.

How much time do I need to get acclimated?
Some people acclimatize quickly, and can ascend rapidly; others acclimatize slowly and have trouble staying well even on a slow ascent. There are factors that we don’t understand; the same person may get AS on one trip and not another despite an identical ascent itinerary. Unfortunately, no way has been found to predict who is likely to get sick at altitude.

Can you prevent altitude sickness?
You may be able to prevent altitude sickness by taking your time when you go to high altitudes, using medicine in advance, and eating certain foods.
-If you are going to altitudes higher than 8000 ft (2438 m), try to spend a night at a medium altitude before going higher. For example, in Peru, spend a couple of nights in Cusco before going to the Inca Trail or the Lares trek.

-Do not fly into high-altitude cities. If this is not possible, avoid large meals, alcohol, and being very active after you arrive. Rest, and drink plenty of liquids. If you have symptoms, do not go higher until they have gone away. Examples of high-altitude cities include Cuzco, Peru and La Paz, Bolivia
-One study showed that starting to take ibuprofen 6 hours before climbing to high elevations and then taking it every 6 hours while climbing may help prevent altitude sickness. Ibuprofen may also reduce the symptoms of altitude sickness if you do get it.
-You may consider taking acetazolamide (Diamox) or possibly dexamethasone before going to a high altitude. Talk to your doctor about this.
-Eat a lot of carbohydrates. This includes bread, cereals, grains, and pasta.

What if you have a lung problem or other disease?
Experts do not know much about how altitude affects other diseases. Many people with allergic asthma do better at high altitudes. Still, if you have asthma and are going to high altitudes, continue to use your daily controller medicine and take your quick-relief medicine with you. Talk with your doctor about altitude sickness if you have long-term diseases, especially heart problems, sickle cell anemia, chronic obstructive pulmonary disease (COPD), or sleep apnea.