Why do people get sick? I believe many people have such doubts. Most people just know what it is and don't know why.
In fact, the life activity of human body is a contradictory struggle process. When normal, the body and the external environment maintain a dynamic balance and are in a healthy state. However, under the action of certain pathogenic factors, the original balance and harmony are broken, and the new contradiction and struggle process between injury and anti injury occurs, which shows the pathological changes in the function, metabolism and morphological structure of tissues and organs, and a series of symptoms and signs appear. This is disease.
The factors leading to diseases include internal and external factors. There are mainly the following:
1. Biological factors. Including pathogenic microorganisms and parasites, bacteria, viruses, Rickettsia, spirochetes, fungi and mycoplasma.
2. Nutritional factors. It refers to the lack or excess of protein, sugar, fat, water, inorganic salts and vitamins required to maintain collective normal metabolism and life activities.
3. Physical factors. Including all kinds of mechanical force, temperature, current, light, sound wave, ionizing radiation or radiation energy, atmospheric pressure change, etc.
4. Chemical factors. Including the direct damage of strong acid, strong alkali and other chemical substances and the poisoning caused by mercury, lead, phosphorus, arsenic, cadmium and polychlorinated diphenol entering the body through the mouth, respiratory tract and skin.
5. Genetic factors. It refers to the abnormality of genetic material, such as chromosome aberration or gene mutation, which can cause genetic diseases.
6. Endocrine factors. It refers to the hypofunction or hyperfunction of endocrine glands and the change of target cell reactivity.
7. Immune factors. Abnormal immune reactions, such as allergy, often cause body damage.
8. Mental factors. Including joy, anger, worry, thinking, sadness, fear and shock, these emotional activities belong to people's normal mental activities, but if they are too intense or last too long, they will cause diseases.
Although there are certain reasons for any disease, sometimes it is caused by a single factor, and sometimes it is caused by a combination of various factors. Most diseases are caused by problems with the immune system. In addition, the cause of disease depends on the human body. Whether it can cause disease also depends on people's resistance. Therefore, it is very important to exercise regularly, maintain a healthy physique and an optimistic attitude.