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What is altitude sickness? Altitude sickness is a frequent pathological illness that occurs due to our bodies unable to acclimatize adequately at high altitudes.

Altitude Sickness

Definition: High Altitude Sickness, or AMS, an abbreviation for “Acute Mountain Sickness,” is a condition caused by a shortage of oxygen at a higher height. It’s also known as mountain sickness. It will be impossible to predict who may suffer from altitude sickness. It can affect anyone; therefore, we can’t predict who will be affected based on factors such as gender, age, or even physical fitness level. Symptoms seldom manifest themselves below 2500 meters (8202 ft.).

At what height does altitude sickness start? Actually, at an elevation of 2000 meters, minor symptoms such as breathlessness might occur. However, altitude sickness manifest itself when we ascend rapidly at high altitude above 2500 m. Thousands of individuals have lose their life due to lack of knowledge. It is not a lethal sickness that may affect to everyone. But you should be careful while ascending over 2500 meters. It can prevent very easily which we will talk later.

Acute Mountain Sickness (AMS): Why It Happens & How High?

Acute Mountain Sickness, in general, is less hazardous if you are cautious in previous phases of symptom. Many people, especially those going to higher elevations, suffer from AMS. It is the mildest and most frequent type of the sickness. Dizziness, headaches, muscular pains, and nausea can all seem like hangover symptoms in the beginning.

Why It happens? there is a density of the air that surrounds you is a barometric pressure. As you ascend to high altitude, the density of air pressure drops and amount of oxygen available decrease.

How high? Altitude sickness may strike anyone who ascend rapidly over 8,200 feet (2,500 m). The symptoms appear gradually as we go high altitude levels.

You become familiar to the air pressure if you reside in an area with a relatively high altitude. However, if you travel to a higher altitude than, your body will require some time to acclimatize to shift in air pressure & to be a normal.

Altitude Sickness Symptom: Who gets it?

“Altitude Sickness” is communal in the sub-alpine (the higher slopes of mountains just below the tree line) & alpine zone (mountain above the tree-line). Acute mountain sickness is a frequent form of altitude sickness that affects roughly 60% of trekkers who trek to high altitudes (above 2,500 meters). The only difference is that some people will experience minor symptoms while others may have severe symptoms.

The oxygen level and air pressure in the atmosphere drop as the height above sea level rises, and the human body must adjust to the new environment over time. In this process, our respiratory system struggles to react to the circumstance by taking as many breaths as possible in order to maintain the proper oxygen level in our bodies. However, we might experience AMS symptoms if it is unable to fully fill the required amount of oxygen.

People who live in hilly or mountainous areas are typically comfortable & habitual to low oxygen levels. Therefore, the pathological condition is uncommon within them. Travelers, trekkers, hikers, guides, porters, aircraft or automobile riders who lives at lower elevations (under 2000 m) and wish to travel to the high mountain at once may suffer from the AMS.

Furthermore, if we do not have the right diet, clothing, footwear, and other necessities, the sickness may spread fast.

What are the Symptoms of Altitude Sickness?

Anybody those who ride or trek uphill rapidly without acclimatization, within 12 to 24 hours symptoms may emerge. Early signs of altitude sickness include a slight headache, tiredness, and dizziness.

If the sickness grips us, we will have difficulty in walking, sleeplessness, and even when we sleep, we will have dyspnea (shortness of breath), a severe headache, a loss of appetite, a lethargic body, nausea, and vomiting.
Be alert & careful early symptom that signal to your body. Otherwise, anyone who ignores & push their body into height or attempts to go higher ahead will face the end of their life due to edema (excess fluid trapped in your body) in brain & lungs.

More Symptoms of AMS are pointed below:

  1. A headache
  2. Loss of appetite
  3. Nausea or vomiting
  4. Sleeplessness
  5. Fatigue or weakness
  6. Dizziness
  7. Shortening breath
  8. Confusion
  9. Loss of coordination
  10. Inability to walk
  11. Aggressive or get angry
  12. Coughing a lot

Altitude Sickness Facts

The fact of altitude sickness is that it can be divided into three types: AMS, HAPE & HACE. According to medical experts, AMS is prevalent in just a few elevation levels. HAPE and HACE, on the other hand, are examined at the severe stage, which chance at higher altitudes.

We need to know the altitude first before we get into depth. From sea level, the true elevation is calculated. Every country in the globe, as we all know, has a unique geographical structure. The earth’s height ranges from sea level to 8848 m, the world’s highest point (Mt. Everest of Nepal). We may categorize altitude into three levels for this discussion.

Altitude Level
1: 2,000 meters (6,562 feet) to 3,500 meters (11,500 ft.)
2: Between 3,500 m (11,500 ft.) and 5,500 m (18,000 ft.)
3: Above the elevation of 5,500 m (18,000 ft.)

The extreme level begins above the elevation of 8000 meters. Many mountaineers apply oxygen cylinders to reach the summit of Mt. Everest, which stands at 8848 meters (29029 ft). Its altitude exceeds the limit, which extends up to the lowest region of the atmosphere called troposphere (the lower boundary of the stratosphere).

  1. Annapurna Base Camp Trek
  2. Everest Base camp Trek
  3. Gokyo Ri Trek
  4. Annapurna Circuit Trek
  5. Upper Mustang Trek
  6. Mardi Himal Trek
  7. Khopra Danda Trek
  8. Kanchenjunga Trek
  9. Manaslu Area
  10. Makalu Trek
  11. Upper Dolpa
  12. Api Himal & others

How to prevent altitude sickness?

It is important to understand about HAPE and HACE before considering precautions or preventive measure. Keep in mind, as we climb higher after 2000 meters (6562 feet), we may get worried mentally. Don’t be concerned; instead, think positively and go on.

Altitude sickness preventive measure

What is HAPE & HACE?

A single term clarifies the differences between pulmonary and cerebral edema. Keep in mind that the term edema refers to swelling in clinical terminology. Furthermore, the term pulmonary refers to the lungs. It is derived from the Latin word Pulmo, which roughly translates to “lung.” If anyone else has a pulmonary disorder, it simply implies that they have an issue with their lungs. Again, the term cerebral denotes a connection to the brain. This disease can manifest itself in some persons at very high altitudes, although the risk is higher at extreme altitudes.

Note: The meaning of edema and oedema is the same; a condition that arise due to an excess of watery fluid collecting in the cavities or tissues of the body. The terms edema and oedema are similar.

HAPE (High Altitude Pulmonary Edema)

“High altitude pulmonary edema,” so often known as “HAPE”. This is another kind of severe altitude sickness that usually occurs in those who have just been diagnosed with acute mountain sickness (AMS).

It’s a condition in which our respiratory system becomes swollen as a result of a build-up of water in our lungs. It’s is the second or last stage of altitude sickness, depending on how you look at it. HAPE is the most serious stage of AMS when compared to regular AMS.

A medical professional is still unsure of the exact reasoning behind why HAPE elicits such a response. According to experts, high blood pressure causes tiny blood vessels to rupture, resulting in fluid accumulation in the lungs.
Those who have already had a chest infection are more likely to become infected due to the puffing up of the lungs in the event of pulmonary edema. Because of the absence of oxygen flow, the lungs soon expand and create dyspnea (breathlessness), and the patient must eventually depart the world.

The following are some of the signs and symptoms of HAPE:

  • A more intense headache
  • Uncomfortable chest
  • Swelling of various organs
  • Fever and shortness of breath
  • A rapid heart rates
  • Coughing that is persistent and dry
  • The color of the lips and nails turns blue.
  • Stool may include blood.

HACE (High Altitude Cerebral Edema)

“High altitude cerebral edema” is abbreviated as HACE. It is most commonly found in those who have acute mountain sickness (AMS). The situation is fluid leaking in a brain cell associated with the head. If anybody have HACE, he/she loses its ability to function properly, causing sufferers to become confused or lose coordination.

We must mediate quickly to stop the swelling process of the brain edema; if not, a brain rupture might lead to death. If you have HACE in high altitude, you feel severe headache & feel like drunkard guyed and willing to lie on bed all day. Shortly, after being unconscious, the patient’s soul goes for all eternity.

The following are some of the signs and symptoms of HACE:

  • Headaches that are unbearable.
  • Memory lapses.
  • Fever
  • It’s possible that your heart rate will rise.
  • Ataxia is a condition in which a person inability to maintain a co-ordination, balance and speech.
  • Eyes are hurting.
  • Unconsciousness and coma are also possible outcomes.

Measures to Prevent Cerebral and Pulmonary Edema

If the symptoms appear to be serious, the right method to avoid getting sick is to go to the doctor right away & take prescription that he or she has recommended. If you are in guided trip, your well-trained tour guides or leaders are also abounding with an aid kit during the trekking session If you are traveling with a reliable trekking company or agency. However, it is preferable to carry or bring your own personal first-aid kit.

Altitude Sickness (HACE)

Altitude Sickness Prevention Medication

If we take enough rest in the early phases, the symptoms may go away. Otherwise, quick descend is the best and easiest way to avoid altitude sickness. While dealing with altitude sickness, garlic or ginger soup, plenty of water, and products containing hot peppers are reported to be extremely beneficial. The individual who is in a critical state must be maintained in a “Pressure Bag” and oxygen must be given.

Before trekking anywhere, talk to your doctor about any medication or health issues. Never hide your health issues to your doctor. Keep in mind that as you go trekking to remote area, there are no hospitals & physicians. “As the altitude rises, easy access becomes more difficult.” Therefore, pre-planning is very essential before going to high altitude.

Medicines such as Diamox (Acetazolamide), Dexamethasone, or Nifedipine are directed if the patient’s start to feel altitude sickness.


Acetazolamide is sold brand name of Diamox. At altitude, irregular respiration is common, particularly when we fall asleep. It plays a vital role to adjust our body in high height by helping to make the blood a bit more acidic. Artificially acidifying the blood helps to maintain the oxygen supply in our bodies. It increases the rate of breathing and exhaling and helps to our body to acclimatize in high altitude.

To avoid AMS, take it 1 day before your trekking to a higher elevation, and then take a couple of doses (as directed by a physician) until the typical symptoms disappeared.

Note: Before using any of these medications, please get medical advice.

Cons: Pain reliever, tingling sensation, tiredness, nausea, and vomiting are some of the few typical side effects, as well the possibility of a kidney infection, sleepiness, and so on.


It is a type of steroid medicine that is considered to be highly strong. Dexamethasone is an anti-inflammatory drug that is used to treat a range of inflammatory diseases such as arthritis, respiratory problems, allergic reactions, skin issues, neurological damage, and chronic lungs disease, & others. Mountain climbers commonly use it to combat the dangers of altitude sickness.

Cons: Blurred vision, increased hunger, dizziness, discomfort, sleeping problems, and menstruation abnormalities are just a few of the side effects of Dexamethasone.

Note: Dexamethasone is a strong drug, you should only take it as directed by your doctor. Make sure you don’t take any more or less than the recommended dosage.


Nifedipine is another type of medicine which is also called calcium channel broker. This medicine can help with pulmonary edema while you’re at a high altitude. It makes a difference by lowering pulmonary arterial pressure. It is not useful in the treatment of cerebral edema. This medication is commonly used to treat excessive blood pressure and chest pain or heart disease. After taking medicine, you should not get up from a laying or sitting posture too fast. Because it has the ability to lower blood pressure instantly.

Cons: This medicine’s adverse side effects include coughing, trouble breathing, dizziness, irregular heartbeat or pulse, headache, and weakness.

Note: If you have a severe coronary artery disease, you should avoid using nifedipine. Before using this medication, speak with your doctor.

Altitude Sickness: What to do?

It will be considerably better if we never get infected with any altitude illness. According to the specialist, to avoid AMS, our speed of walk above 2500 meters (8202 feet) must be moderate, not going 300 meters (984 feet) per day. However, above 4000 m (13123 ft), our daily ascent rate must be 150 m (492 ft.).

But, while trekking in Nepal, such as Everest Base Camp Trek, Annapurna Base Camp Trek, Annapurna circuit etc. Everyday hiking will be around 300 m (984 ft) to Maximum 500 meter (1640 feet) per day according to the itinerary provided by agencies.

Altitude Sickness Home Remedies

Take a break for a few minutes while strolling, drink lots of water to combat with dryness and moisture. When the first signs of altitude sickness arise, don’t try to climb uphill; instead, carefully stay at lower elevation a few meters and recover next day. If possible or accessible, get counsel from a medical professional or from your expert trek guide or leader.

Keep in Mind: Those who have high blood pressure, heart disease, diabetes, or lung illness should seek medical counsel before embarking on the trek.

Care for Altitude Sickness

How to care for altitude sickness? Here, I’ve attempted to collect the topics pertaining to prevention & care that will be important in your life. Please take the time to read it carefully and remember to bookmarks and share it.

  • It’s never a good idea to try to climb quickly.
  • Alcohol, cigarettes, cigars, narcotics, and other habitual items that are harmful to one’s health should avoid.
  • Pregnant women should not sleep at elevations higher than 3700 meters (12139 ft).
  • Maintain a healthy mental state (Mentally fit yourself).
  • When you’re at a higher height, eat a high-calorie meal. For instance; Dhal Bhat, Spaghetti etc.
  • Keep your body hydrated by drinking enough of water or soup
  • Always choose to spend the night at a lower altitude compared to the daylight ascent.
  • Descend at least half a mile from the location where the AMS symptom identified.
  • Drink lots of water and take a break.

Altitude Sickness Treatment

Keep patients inside for at least 2 hours if a Pressure Bag or Gamow bag is available. During the therapy process, 6 liters of oxygen per minute must be provided. Consult a physician for medical advice.

After 2500 meters (8202 feet) of elevation, your hiking pace must be slow, not above 300 meters (984 feet) per day, to avoid altitude sickness. After reaching 4000 meters (13123 feet), your daily ascent rate should be 150 meters (492 feet).

Some of the newcomers to the group in a guided trip or with their small group, they seek to conceal their AMS symptoms & continue with them. It’s important to keep in mind that everyone’s acclimatization capability is different. Always communicate with one another and never hide any signs of sickness.

Many young tourists believe that altitude sickness affects mainly the elderly, which is untrue. According to experts, the size of the brain shrinks as individuals age, allowing more space for it to expand, resulting in a lower risk of injury. It might be partially correct, but not entirely. As I previously stated, symptoms are not limited to age, sex, or physical fitness. Being young, strong & fit doesn’t help. Medicine is not substitute for descent.