What is altitude sickness?
Altitude sickness refers to a series of natural physiological responses that occur when a person reaches a certain altitude, as the body adapts to changes brought on by the altitude—such as differences in air pressure, reduced oxygen levels, and dry air. Symptoms of altitude sickness generally appear 6–12 hours after reaching elevations above 3,000 meters, with a few occurring 1–3 days later. Recovery usually takes 3–7 days, but in severe cases, it may take over two weeks. Common symptoms of altitude sickness include chest tightness, shortness of breath, dry cough, headache, dizziness, fatigue, loss of appetite, nausea, vomiting, drowsiness, insomnia, and mild fever. Most people will experience bluish lips and nail beds due to lack of oxygen, while others may suffer from rough skin, chapped lips, and nosebleeds due to the dry air. In severe cases, symptoms may include dulled senses, restlessness, mental agitation, impaired thinking and memory, abnormal taste, smell, hearing, and vision, hallucinations, as well as possible edema, shock, or convulsions. The symptoms and severity of altitude sickness vary from person to person. Some may experience only one or a few of the above symptoms, while others may have more; some react sensitively and intensely, while others have milder or even almost no symptoms.
Prevention of Altitude Sickness
1. Maintain a Good Mental StateIf you are overly nervous, constantly worried, or overthinking, and panic at the slightest discomfort—giving yourself negative psychological cues—it can actually worsen physical discomfort and prolong recovery. In fact, many symptoms of altitude sickness are related to psychological factors. Also, avoid being overly excited or impulsive. For those new to high altitudes, do not get overly thrilled or emotional upon seeing the plateau or snow-capped mountains—screaming, shouting, or jumping around will only lead to hormonal imbalance, increase the burden on your heart and lungs, and worsen altitude sickness.
2. Drink Plenty of WaterDuring high-altitude activities, adequate hydration helps maintain your body’s balance, ensures smooth blood circulation, improves oxygen supply capacity, reduces the burden on your heart and lungs, quickly eliminates toxins, and allows you to adapt to the high-altitude environment in a very short time, relieving the pain of altitude sickness and restoring good condition and stamina. It’s no exaggeration to say that water is the best remedy against altitude sickness. Generally speaking, you should drink at least 2–3.5 liters of water per day at high altitudes. Proper hydration can be judged by whether your urine output is sufficient and whether your urine is clear or at least light yellow. In addition to plain water, you can also add glucose, American ginseng slices, Isatis root granules, or fruit-flavored drinks to replenish energy, enhance disease resistance, and prevent colds.
3. Stay WarmThe weather on the plateau is characterized by low temperatures—generally, the temperature drops by 5–6°C for every 1,000 meters of altitude gained—and large temperature differences between morning and evening, as well as day and night. Weather changes rapidly; the sun may be shining brightly one moment, and soon there could be strong winds, thunderstorms, or hail. Therefore, it’s essential to stay warm and guard against catching a cold on the plateau. Bring enough warm clothing, change clothes frequently, and adjust layers promptly, following the principle of “better warm than cool.” On the plains, the habit is to “put on more clothes when you feel cold,” but on the plateau, you should change to “take off clothes when you feel hot.” Additionally, try to bathe and wash your hair as little as possible. At high altitudes, the body’s functions are imbalanced and immunity is lowered, making it very easy to fall ill.
4. Eat a Balanced DietIn the oxygen-poor environment of the plateau, human metabolism is affected, so the digestive functions of the stomach, intestines, liver, and gallbladder are weaker compared to those at lower altitudes, reducing the ability to digest and absorb food. On the contrary, the body consumes more energy and vitamins at high altitudes compared to sea level. Therefore, when arranging meals at high altitudes, you need to consider the tolerance of your digestive system and also focus on improving your nutritional intake. Your diet should include more carbohydrates (should account for over 60%) and higher plant-based protein, along with increased intake of various vitamins to quickly provide energy and improve the body’s adaptability. Avoid overly greasy foods. Excess fat and animal protein not only burden the stomach and intestines but can also worsen altitude sickness. It’s best not to eat too much at high altitudes; maintaining a “70% full” state is ideal.
5. Sleep Late and Rise Early Nights on the plateau are often harder than the days, and sleeping becomes uncomfortable. Environmentally, nighttime air pressure is lower, and with weakened photosynthesis, oxygen levels in the air further decrease. From the body’s perspective, during the day when you’re awake, you can consciously regulate your breathing to ease hypoxia. But at night, once asleep, your breathing gradually slows to near-sea-level frequency, leading to hypoxia and affecting sleep quality.A better approach is to go to bed about an hour later than your usual habit. While ensuring warmth, make sure your room or tent has good ventilation. You can open windows slightly in a room or fully open vents in a tent, leaving a slight gap in the zipper if necessary. The air on the plateau is already thin, and staying in an enclosed space where you’re breathing the same limited volume of air can easily cause headaches and other discomforts.
6. Necessary Medication for Supportive TreatmentFor those new to the plateau, you can start taking medications like Gao Yuan An (Plateau Peace) or Hong Jing Tian (Rhodiola) 1–3 days before entering high-altitude areas. Strictly guard against catching a cold, as even a mild respiratory infection can increase the risk of high-altitude pulmonary edema. If you notice early signs of a cold, take anti-cold medication immediately. Waiting until symptoms worsen usually renders the medication ineffective. For altitude sickness-induced headaches, you can use pain relievers like Excedrin. If the reaction is severe, it’s still advisable to see a doctor nearby. It’s also recommended that those with moderate symptoms avoid oxygen supplementation if it's not dangerous and they can tolerate it, and instead try to rely on their own adaptation. Once you start using oxygen, dependency can be quite strong, and you might find it hard to function without it on the plateau in the future.
Not everyone will experience altitude sickness, and the degree of reaction varies from person to person. It’s recommended that everyone refer to the suggestions above and take appropriate preventive measures based on their own physical condition when traveling.