Inca Trail Altitude Sickness also known as Inca Trail acute mountain sickness (ITAMS) occurs when your body cannot obtain sufficient amounts of oxygen from the air that you breathe to allow normal bodily functions. As the altitude increases, the percentage of oxygen in the air reduces, making any physical problems one may be experiencing even more severe.

The Inca Trail Altitude Sickness can affect anyone and there are no specific factors such as age, sex, or fitness level that enable you to know if you are likely to suffer. Most trekkers can go up to 2500m to 3000m with little or no problems. If you have experienced altitude sickness previously, then under similar conditions you are likely to experience altitude sickness again.

Every year trekkers spoil their Classic Inca Trail to Machu Picchu because they do not listen to their bodies. With a sensible approach, trekking at higher altitudes is not dangerous and is not uncomfortable as altitude sickness is largely preventable. If you experience any physical discomforts that you think could be related to Inca Trail Altitude Sickness, please inform your guide. Our guides have experience with Inca Trail Altitude Sickness, and it is important that you listen to their advice so that we can minimize any symptoms.

Our guides have experience with Inca Trail Altitude Sickness, and it is important that you listen to their advice so that we can minimize any symptoms.

The following Inca Trail Altitude Sickness information is the consensus among experienced trekkers but is not intended to replace the advice of a medical professional. Consult a doctor before trekking at high altitudes or using any medications.

  1. Drink 5 Liters of Water Per Day

Quite simply, drink a minimum of five liters of water per day, no matter what. This is easier at lower elevations when it’s hot, but becomes more burdensome when temperatures cool off and you perspire less. After a few liters you may feel properly hydrated, but your body is doing extra work with less oxygen and needs the water. Force down five liters per day, without exceptions.

  1. Avoid Dramatic Gains in Elevation

Treks at altitude should avoid big single-day gains in elevation (more than 1,500 vertical feet). A common misconception about trekking at high altitude is that physical condition dictates the body’s ability to fend off altitude sickness. This causes many people who are “in good shape” to ignore the rules of acclimatization, go too high too fast, and have problems. Your itinerary should factor in altitude gains and consequently some hiking days will end early. Embrace the pace, rest your legs, and hydrate.

  1. Climb High, Sleep Low

You will acclimatize better if you expose yourself to higher altitudes but return to a lower altitude to sleep. After setting up camp, scramble up a nearby hill, scope out the scenery, and head back down for a better night’s rest. When you have a rest day, use the opportunity to hike to higher elevations and back down—even a few hundred vertical feet is worth the effort. At higher altitudes—around 10,000 feet and above—this rule becomes even more important as your body is learning to cope with considerably less oxygen.

  1. Eat, Eat, Eat…

Your body is doing more work than usual so make sure to stay nourished and full of carbohydrates. For a dependable snack, The Classic Inca Trail has embraced the Snickers bar wholeheartedly and it can be found even in the campsites (and for very cheap). Too much sugar, yes, but full of good things like nuts and chocolate. Do a good deed and buy some for your porters and guide whenever possible.

  1. Listen to Your Body

By following the above rules, you will greatly increase your odds of staying healthy throughout your trek, but everybody reacts differently to altitude so pay close attention to how you feel. Every trek should have rest days built in and you shouldn’t be afraid to use them. Stay hydrated, wear sunscreen, and have layers available for protection from the powerful sun. Avoid alcohol and other substances. Monitor yourself and always communicate any health concerns to your group.

An estimated 75% of people feel some effects of Inca Trail Altitude Sickness, mostly in the form of headaches, nausea, fatigue, and trouble sleeping. These are actually mild manifestations of Inca Trail Altitude Sickness (ITAMS).  Mild ITAMS should not interfere with normal activity and the symptoms should subside as acclimatization occurs. As long as the symptoms are mild, it’s generally okay to continue hiking up at a moderate rate. If feeling poorly persists or worsens, turn around.

Our guides have experience with Inca Trail Altitude Sickness, and it is important that you listen to their advice so that we can minimize any symptoms.

  Medications for Inca Trail Altitude Sickness


To help prevent altitude sickness, the best measure is to spend two nights or more at each rise of 1,000m. Alternatively, take 125 mg or 250 mg of acetozolamide (Diamox) twice or three times daily starting 24 hours before ascent and continuing for 48 hours after arrival at altitude. Possible side effects include increased urinary volume, numbness, tingling, nausea, drowsiness, myopia and temporary impotence. Acetazolamide should not be given to pregnant women or anyone with a history of sulfa allergy. For those who cannot tolerate acetazolamide, the next best option is 4 mg of dexamethasone taken four times daily. Unlike to acetazolamide, dexamethasone must be tapered gradually upon arrival at altitude, since there is a risk that altitude sickness will occur as the dosage is reduced.



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