Altitude Sickness

Altitude sickness is also known as Acute Mountain Sickness (AMS) and is caused by the decreasing amount of oxygen at altitudes above sea level, usually ranging from about 3,500 meters, which may result in a mild headache and weariness to a life-threatening build-up of fluid in the lungs or brain, and even fatality at moderate to high altitudes.

Altitude sickness typically occurs when a person rapidly ascends to high altitudes, normally above 8,000 feet. Mountain climbers are at risk of developing altitude sickness (also known as mountain sickness), which may be harmful or even more fatal if its onset is ignored. Altitude sickness is caused by gaining altitude too quickly, which doesn’t allow the body to adjust to the atmosphere with low oxygen levels. It often occurs when individuals are not accustomed to high altitudes and rapidly transition from lower altitudes to higher ones. For example, you may get a headache when you drive over a high mountain pass, hike to a higher altitude, or arrive at a mountain resort.

Altitude sickness can be dangerous, so it is a smart move to take special care if you go hiking or camping in the high Himalayas at high altitudes. Mild altitude sickness is common, and even experts do not know who will get it and who will not get altitude sickness.

Why does altitude sickness happen?

If you climb higher at a rapid pace, your body does not get enough time to acclimate properly.

• Low oxygen level
• Dry and cold air
• Low air pressure
• Increased breathing and heart rate

Three Types of Altitude Sickness

1. Acute Mountain Sickness (AMS)

AMS is the mildest form of altitude sickness and is commonly experienced by peak climbers or trekkers. It usually begins 12 to 24 hours after arriving at a higher altitude. They lessen in a day or two as your body adjusts. If AMS is ignored and the ascent continues, it can progress into more dangerous conditions.

Symptoms of acute mountain sickness (AMS)

• Dizziness
• Fatigue and loss of energy
• Shortness of breath
• Loss of appetite
• Sleep problems

2. High-Altitude Pulmonary Edema (HAPE)

High-Altitude Pulmonary Edema is a buildup of fluid in the lungs that can be very dangerous and even life-threatening. As oxygen levels drop, the blood vessels in the lungs become constricted, leading to increased pressure that forces fluid into the air sacs. This makes breathing extremely difficult. This is the most common cause of death from altitude sickness.

Symptoms of High Altitude Sickness (HAPE )

• Cyanosis is when your skin, nails, or whites of your eyes start to turn blue.
• Confusion and irrational behavior
• Shortness of breath even while resting
• Extreme fatigue and weakness
• Feeling like you’re suffocating at night
• Persistent cough, bringing up white, watery fluid.

3. High-altitude Cerebral Edema (HACE)

 High-altitude Cerebral Edema is the most severe and life-threatening form of altitude sickness, caused by swelling of the brain due to a rapid rise to high altitude without proper acclimatization. This happens when there’s fluid in the brain. It is too life-threatening, and you need to seek medical attention right away.

Symptoms of High Altitude Cerebral Edema (HACE)

• Headache
• Loss of coordination
• Weakness
• Disorientation, memory loss, hallucination
• Psychotic behavior
• Coma

Altitude sickness medication

Altitude Sickness is common in travelers who enjoy traveling at higher altitudes. Mostly, the people who are on an adventurous trip, trekking, and peak climbing. That’s why travelers should be well informed about the medications for altitude sickness.

The medicines for high altitude sickness include:

• Acetazolamide: To prevent and treat high-altitude sickness
• Ibuprofen and paracetamol: For headaches
• Anti-sickness medicine, such as promethazine, for nausea.

Begin taking acetazolamide 1 to 2 days before you start to go up to high altitude, and continue to take it while going up. You should still go up gradually and follow the prevention advice, including taking time for acclimatization, having regular rest days, and drinking plenty of water.

If you get symptoms of altitude sickness while taking acetazolamide, rest or go down until you feel better before going up again.

If you think you have high altitude sickness, then,

• Stop and rest where you are
• Do not go any higher for at least 24 to 48 hours
• If you have a headache, take ibuprofen or paracetamol
• If you feel sick, take an anti-sickness medicine such as promethazine
• Make sure you are drinking enough water
• Do not smoke, drink alcohol, or exercise

For Complication cases, HAPE and HACE:

The symptoms of HAPE can start to appear a few days after arrival at a higher altitude. It can be fatal if it’s not treated immediately.

It can be treated by the following:

• Move down to a lower altitude immediately
• Take nifedipine
• Give bottled oxygen if available

Nifedipine is a medicine that helps to reduce chest tightness and make breathing easier. It’s also often part of an expedition’s medical supplies. You should go hospital as soon as possible for follow-up treatment.

A person with HACE will often not realize they’re ill. HACE can develop quickly over a few hours. It can be fatal if it’s not treated immediately.

It can be treated by the following:

• Move down to a lower altitude immediately
• Take Dexamethasone
• Give bottled oxygen, if available

Dexamethasone is a steroid medicine that reduces swelling of the brain. It’s often carried by professional mountain climbers as part of their medical supplies. If you cannot go down immediately, dantrolene can help relieve symptoms until it’s safe to do so. You should go to the hospital as soon as possible for follow-up treatment.

Who Is Most at Risk of Altitude Sickness?

Altitude sickness can affect anyone, but few people are more vulnerable than others. Trekkers who go up too quickly without giving their bodies enough time to adjust are at the highest risk. Individuals with a history of altitude sickness, even on previous trips, are also more likely to experience symptoms again. 

People with certain underlying conditions, such as respiratory issues, anaemia, or low fitness levels, may struggle more at high elevations because their bodies already work harder to deliver oxygen. Those who are dehydrated, fatigued, or not eating well during the trek are also more prone to feeling the effects of altitude. 

Interestingly, age, gender, or physical strength do not guarantee protection; even very fit athletes can get sick if they rush the ascent. In short, altitude sickness doesn’t discriminate, but poor pacing, lack of acclimatisation, and pre-existing health factors can significantly increase the risk.

Ideas to be safe from Altitude sickness

The best way to be safe from altitude sickness is to ascend slowly once you are more than 3,000 meters above sea level. Advance for only 300 meters or less per day. Be sure to take an extra day of rest and acclimatization after completion of every 1,000 meters.

1. Training (Meditation and breathing yoga)

To be in good physical condition while trekking at a higher altitude is always effective. If you are in good physical condition, then you are more likely to catch altitude sickness, but if you are a regular gym guy and have proper physical fitness, then you have less chance of catching altitude sickness. Before starting any of the adventurous trips in the high Himalayas, you should do training activities like hiking and walking at higher elevations.

You will be used to higher elevations, which keeps you away from the chance of altitude sickness. However, some people swear by doing yoga and meditation to deal with altitude sickness. Doing poses that turn you upside down makes the blood rush to your brain. Pranayama or deep breathing exercise may also help with shortness of breath, bringing more air into your lungs. Practicing all types of yoga or meditation techniques is a great way to improve your breathing.

2. Proper acclimatization

Acclimatization is the best way to be safe from altitude sickness, as it gives us enough time for our bodies to adjust to the environment at higher altitudes. High altitudes and lower air pressure cause fluid to leak from the capillaries, which can cause fluid build-up in both the lungs and the brain. Continuing to higher altitudes without proper acclimatization can lead to potentially serious, even life-threatening illnesses. To properly oxygenate the body, your breathing rate (even while at rest) has to increase.

Therefore, you have to acclimatize properly during your climbing or trekking activities in the high Himalayas. Acclimatizing doesn’t mean you have to stay and take a rest; it means you can ascend slowly by avoiding more than 500 meters in a day. And take the rest of the extra days after every subsequent 1,000-meter climb.

3. Avoid smoking, alcohol, and caffeine

Alcohol, smoking cigarettes, and caffeine can make altitude sickness symptoms worse. With the consumption of cigarettes, alcohol, and caffeine, breathing becomes difficult because you are not taking in as much oxygen. Drinking alcohol, smoking cigarettes, and consuming caffeine at high altitudes do, however, exaggerate and enhance the dehydration many feel when they increase their elevation.

This can affect one’s physical and cognitive well-being, which may cause him or her to be unable to walk safely. That’s why it is better to avoid alcohol, smoking, and caffeine consumption to stay hydrated and stay away from altitude sickness. If you need to drink alcohol, you can wait for 24 to 48 hours so that your body can adjust to the environment.

4. Drink a penalty of water

Staying hydrated is also very important in preventing altitude sickness. Altitude increases water losses from the lungs due to the cold and dry air. Drink enough water regularly during your climb at higher altitudes. The body’s requirement for fluids is very high at altitude, often exceeding 4 liters of water per day. Water increases the volume of blood to oxygenate. By drinking water or getting hydration, you can increase your blood oxygen levels to help you recover from altitude sickness faster.

5. Eat a high-energy diet

Although high-fat foods are energy-dense, fat is not tolerated well at altitude and can worsen the symptoms of Acute Mountain Sickness (AMS). Travelers at higher altitudes are highly recommended to consume food rich in carbohydrates, as it is the preferred energy source at higher altitudes. Carbohydrate replaces depleted muscle glycogen, prevents the muscle from being used as energy, and requires less oxygen for metabolism.

A high-carbohydrate diet can reduce the onset and severity of Acute Mountain Sickness and improve physical performance. Besides this, protein food is also recommended as it carries a high amount of calories, which is a source of energy as well. ·

6. Avoid hard exercise

To exercise at a high altitude means working in an environment with reduced atmospheric pressure. You should take precautions to avoid becoming sick or injured at altitude. At high altitudes, your body needs to work extra hard to take in the same amount of oxygen as you are accustomed to at sea level.

Oxygen levels at higher altitudes (above 2,500 meters) are lower than they are at sea level, which will cause your breathing rate to increase and will cause you to become tired much more easily.

Therefore, doing hard exercise at higher altitudes should be avoided to stay away from the risk of high-altitude sickness.

7. Proper sleep

Altitude sickness usually get worse at night when you are sleeping, as many high-altitude climates are extreme and dangerous. It's a good idea to do a higher climb during the day and then return to a lower altitude to sleep, especially if you plan on climbing more than 1,000 feet in one day. Sleeping at altitude provides enough exposure to stimulate the production of new red blood cells, whilst allowing you to maintain training quality at sea level.

Therefore, it is good to have proper sleep at lower altitudes or return to a lower altitude to sleep, where your body can adjust to the atmosphere because there can be a disturbance in sleep due to high air pressure and the presence of low oxygen in the higher altitudes.

8. Trek at your own pace

There is a saying slow and steady wins the race so you can move slowly at higher altitudes by having proper rest. Your body needs about two to three days to adjust to the changes. Altitude sickness occurs if you ascend too high and too fast. Trek or climb within your body's capacity, as anyone, even people with good physical fitness, can get altitude sickness at higher altitudes.

Above 3,000 meters, most experts agree that you shouldn’t ascend more than around 300-500 meters in a day. You should allow an acclimatization day for every 1,000 meters of height gain, and move slowly upward steadily at a consistent speed.

9. Consult with a doctor before starting a high-altitude trek

Trekking trail in the Himalayas goes to higher altitudes, and there are no hospital facilities or health institutions for any unexpected incident. If you are taking some particular medicine regularly, you should bring it with you.

Moreover, it is better to consult with your doctor of all the updates about your physical condition, or they may have updated the medication list. Any regular medicine prescribed by your physician must be taken along with you for your Himalayan Trekking in Nepal. Concerning your safety, your doctor will recommend the best altitudes you should trek that your physical condition can handle.

How Guides Help Prevent Altitude Sickness?

Trekking with an experienced guide can make a world of difference when it comes to staying safe from altitude sickness. Local guides understand the altitude from years of real-life experience. They know how fast or slow you should walk, when to rest, and exactly how your body may react as you gain elevation. A good guide constantly observes your breathing, walking pace, appetite, how you speak, and recognises early warning signs long before you notice them yourself. They encourage proper hydration, remind you to eat even when you don’t feel hungry, and plan the day’s pace to match your body’s needs.

Guides also make smart decisions regarding acclimatisation days, adjusting the route if someone feels unwell. They know the safest tea houses, where clean drinking water is available, and when weather conditions might make your body more vulnerable to altitude effects. If symptoms appear, a trained guide knows exactly what to do, whether it’s rest, descent, medication, or emergency evacuation.

In the mountains, these quick decisions can save lives. Their presence gives trekkers confidence and security, which allows the journey to be enjoyable rather than stressful.

High Altitude Sickness FAQ

Should I be worried about altitude sickness?

You shouldn’t be worried about altitude sickness as our expert guides will help you in every possible way. When the symptoms of altitude sickness begin, our well-experienced guide will provide you with first aid and medicine like Acetazolamide, which is best to treat altitude sickness, ibuprofen, and paracetamol for headache, and promethazine for nausea.

If there is an emergency, then the guide will suggest you descend faster or take you to the hospital in serious cases.

What increases the risk of altitude sickness?

The risk of altitude sickness increases when climbers or trekkers ascend quickly at a higher altitude without proper rest. A quick change in the air pressure and a lack of oxygen in the air, and people who have a prior history of high altitude sickness, as well as people who have a medical problem that affects breathing, increase the risk of altitude sickness for anyone.

What causes altitude sickness?

Altitude sickness is caused by low oxygen levels in the air at altitudes above about 2,500 meters. It occurs when the body has not had time to adjust to less oxygen.

Is there any medication to prevent altitude sickness?

Acetazolamide, or Diamox, is the standard medical prophylaxis agent for high-altitude sickness. The medication is effective in preventing all types of altitude sickness, which include: Acute Mountain Sickness (AMS), High Altitude Pulmonary Edema (HAPE), and High Altitude Cerebral Edema (HACE).

At what height does altitude sickness start?

Symptoms of altitude sickness usually develop between 6 to 24 hours after reaching altitudes more than 2,500 meters above sea level. Normally, the higher chance of altitude sickness starts after ascending 3,500 meters above sea level.

How do you fix altitude sickness?

To fix the high altitude sickness, stop at the point where you feel altitude sickness, if possible, descend to a lower altitude, take enough rest, drink plenty of water, and take high-diet soup; all these ideas help to fix altitude sickness.

What are the 3 stages of altitude sickness?

There are three stages of altitude sickness which are Acute (mild) or Mountain Sickness (AMS), High Altitude Pulmonary Edema (HAPE), and High Altitude Cerebral Edema (HACE).

How do you get rid of altitude sickness?

The best way to get rid of altitude sickness is to plan for a higher altitude. The following are the tips to get rid of altitude sickness;

• Avoid drinking alcohol, smoking, and tobacco consumption
• Drink twice as much water
• Acclimate before heading up
• Ascend slowly
• Talk to your doctor

What is the fastest way to adjust to high altitude?

You can adjust quickly and safely to high altitudes by following the steps:

• Drink lots of water
• Reduce your exercise
• Get enough sleep
• Limit your alcohol intake
• Protect yourself from the sun
• Eat enough calories
• Acclimatize after every 1,000 meters above an altitude of 2,500 meters

How long does it take to acclimate to high altitude?

Given time your body can adapt to the decrease in oxygen molecules at a specific altitude is known as acclimatization. It takes 1 to 3 days to acclimate properly at that altitude.

What are the 3 stages of acclimatization to high altitude?

The three stages of acclimatization to high altitude are the preparation stage, the ascent stage, and the descent stage.

What happens to your body at a high altitude?

You will likely feel nauseous and light-headed, and you may vomit and have a headache. Different levels of altitude sickness have different symptoms: Symptoms of mild, short-term altitude sickness usually begin 12 to 24 hours after arriving at a high altitude.

What is the best medicine for altitude sickness?

The best medicine for altitude sickness is to move to a lower elevation as quickly and safely as possible. At the very least, do not go higher. If symptoms are mild, staying at your current elevation for a few days might be enough to improve the symptoms. It is better to take Acetazolamide before climbing or at higher altitudes.

Who should avoid going to high altitudes?

Heart patients who are never physically active shouldn’t start being active while at high altitudes. Evidence suggests that heart failure patients should avoid climbing more than 300 to 500 meters a day when in high-altitude locations, since drastic elevation changes can worsen the symptoms. Besides this, people who live at low elevations should avoid high altitudes since their body isn’t used to higher altitudes and they have a greater risk of symptoms.