Symptoms of plateau hypoxia

Usually after holidays, people will travel to a plateau area. The plateau is indeed worth a visit because the plateau has a rich environment and people living there. Not only can you experience the local characteristics, but you can also breathe fresh air. However, when you really get to the plateau, you will find that the higher you go, the more difficult it will be to breathe, and you will also feel out of breath. The symptoms of plateau hypoxia are one of them.

Overview

There are many natural characteristics on the plateau. When people living in the plains enter the plateau, the human body must make a series of adaptive adjustments under the conditions of low pressure and hypoxia in order to adapt to life on the plateau. During the process of adjustment and adaptation, some clinical symptoms (also called stress responses) may appear. The degree of these responses varies significantly depending on each person's age, gender, health status, mental state and other factors.

Specific manifestation

After entering the plateau from the plains, the regulatory changes that occur in the human body are mainly manifested in the following aspects:

1. Changes in the respiratory system. In the plains, a normal person breathes an average of 18 times per minute. In mild hypoxia, the first symptom is deeper and faster breathing. As the hypoxia worsens, the frequency also accelerates further. People may feel chest tightness and shortness of breath. After adaptation, they gradually return to the original level. The increase in lung ventilation is a compensatory adaptive function of the human body under hypoxic conditions.

2. Changes in the circulatory system.

(1) Pulse (heart rate) frequency: The normal pulse rate of a person in the plains is 72 beats per minute, which is four times the number of breaths. When entering the plateau, the heart increases the number of contractions to ensure the blood oxygen supply to tissues and organs. When you first arrive at the plateau, your pulse rate may increase to 80-90 beats per minute, and in some individuals it may reach more than 100 beats per minute. After living there for a period of time, it will recover.

(2) Blood pressure: The normal systolic blood pressure of people in the plains is 110-120 mmHg, and the diastolic blood pressure is 70-80 mmHg. When people first enter the plateau, the blood vessels in the skin, abdominal organs, etc. contract due to the influence of vascular receptors and body fluids, and blood pressure rises, thereby ensuring the blood supply to the coronary arteries of the heart and cerebral blood vessels. You can return to normal after adaptation. Due to the large changes in systemic circulation, pulmonary circulation and microcirculation under plateau hypoxia conditions, blood pressure is also unstable, which is inseparable from the functional state of microcirculation. Therefore, the blood pressure value in the mainland cannot be used as the plateau standard, and blood pressure cannot be determined as high blood pressure or low blood pressure after measuring it twice.

(3) Changes in blood count: In plain areas, the normal value of red blood cells for men is 4.5-5 million/m3

meters, 3.5-4.5 million/cubic millimeter for women, hemoglobin 12-14.5 g% for men and 11-13 g% for women. Values ​​below this value are anemia, and values ​​above this value are polycythemia. The values ​​increase with increasing altitude. According to the survey results of Tibet Medical Institute between 3658 meters and 4700 meters, the red blood cell count increases by approximately 130,000/cubic millimeter and the hemoglobin increases by approximately 0.36 g% for every 100 meters increase in altitude. A certain increase in both on the plateau is still a physiological phenomenon and is beneficial to the human body. If it increases beyond a certain limit, it will cause hemodynamic changes and develop into pathological changes, then a series of clinical symptoms will appear, such as plethora of facial features, palpitations and shortness of breath, and cyanosis of fingers. At this time, certain treatment measures must be taken.

3. Changes in the digestive system: After entering the plateau, the secretion of the digestive glands and gastrointestinal motility are inhibited. Except for a slight increase in pancreatic secretion, the secretions of other digestive foods such as saliva, intestinal juice, and bile increase compared to the plains, and the gastrointestinal function is significantly weakened. Therefore, a series of digestive system disorder symptoms such as loss of appetite, abdominal distension, diarrhea or constipation, and upper abdominal pain may occur. After living in the plateau for a period of time, they can gradually recover. In a few people, these symptoms persist for a long time or recur.

4. Changes in the nervous system: The central nervous system, especially the brain, is extremely sensitive to hypoxia. In case of mild hypoxia, the excitability of the entire nervous system increases, such as emotional tension, irritability, euphoria, etc., followed by headaches, dizziness, insomnia, forgetfulness, etc. When reaching higher altitudes, the process changes from excitement to inhibition, with symptoms such as drowsiness, apathy, and slow reaction. A few people suffer severe loss of consciousness or even coma, but they recover after moving to lowland areas. The severity of neurological symptoms is often closely related to one's psychological state and mental mood. For example, people who are afraid of the plateau and lack the mental preparation and determination to overcome the plateau will have more reactions. On the contrary, those who sing and laugh all the way to Tibet and are in a good mood will have fewer reactions. But they can recover after a period of adaptation.