Why do people catch a cold? Why do some people catch a cold repeatedly?
Let's meet a cold first. Cold is a respiratory disease caused by virus or bacterial infection, allergic reaction and so on. It can be divided into common cold and influenza. Influenza is caused by influenza virus infection. The common cold is more complicated. The pathogens causing colds include a variety of bacteria and viruses, especially viruses.
Common viruses that can cause colds include rhinovirus, coronavirus, influenza virus, partial lung virus, respiratory syncytial virus, adenovirus, coxsackievirus, ECHO virus, enterovirus and so on. Generally, after virus infection, the resistance of human upper respiratory tract mucosa decreases. At this time, bacteria can take the opportunity to enter and cause more serious bacterial infection. Due to the differences of infection of different viruses and individual reactions, the symptoms of colds will also be different. There are often symptoms such as nasal congestion, runny nose, cough, sneezing, pharyngeal discomfort and fever in severe cases.
When autumn and winter seasons or seasons alternate, the weather is cold and changes rapidly, and the human body is difficult to adapt. At this time, it is easy to catch a cold. Especially for the elderly, infants and those with congenital physical weakness, they are more likely to catch a cold and often occur. For example, infants and children are less immune than adults due to incomplete growth and development, so they are easy to be infected and induce diseases when encountering pathogens such as viruses and bacteria.
The elderly often suffer from the gradual degradation of organ functions and the troubles of some chronic diseases, which greatly reduce their immunity and are also prone to colds. In addition, modern people have tense life, high work pressure, often stay up late, work in an air-conditioned environment for a long time, lack of necessary exercise, etc., which can lead to physical decline, weakened body resistance and easy to catch a cold.
If a person often catches a cold, in addition to the low immunity of the body, the cold virus itself is also an important influencing factor. It is understood that 90% of colds are caused by virus infection. Generally speaking, after the cold virus invades, the human body can produce antibodies against the virus. Without serious complications, the cold can heal itself. However, the antibody of cold virus cannot remain in the human body for a long time, and the immune effect of the antibody is specific. It can only target a specific virus, but has no immune effect on other pathogens. There are many kinds of viruses that can cause colds. When the human body is cured of one virus, it may be infected by another virus.
Therefore, people may catch cold repeatedly in a short time. In addition, some influenza viruses (such as influenza viruses) are prone to mutate, and even if the human body is infected with the virus, they are immune to certain diseases. Because of the variation of the virus itself, it can evade the attack of the body's immune system and trigger a cold again.
The incubation period of a cold is 1-3 days. Usually, symptoms such as throat discomfort or headache first appear, followed by other symptoms. It is the most serious on the third and fourth days, and generally can be cured in about 1 week. Because there are many pathogens causing colds, there are no specific and effective drugs for colds. Generally, the drugs for treating colds only reduce symptoms. Therefore, preventing colds is more important and effective than treating colds.
So how to prevent colds? There is no doubt that improving the body's resistance is the most important. Specifically, we should pay attention to balanced nutrition and eat more milk, eggs, fruits, vegetables and other foods rich in protein, inorganic salts and vitamins to prevent the decline of resistance due to malnutrition. We should also take proper physical exercise, participate in more outdoor activities, bask in more sunshine (sunshine has a certain bactericidal effect and can promote calcium absorption), and breathe more fresh air. Through appropriate exercise to enhance their physique and prevent the occurrence of colds. Paying attention to personal hygiene and developing good hygiene habits are also important measures to prevent colds. For example, wash hands frequently, dry bedding frequently, maintain indoor air circulation, cover your mouth and nose when sneezing, wear masks, try not to go to crowded places, and so on. In addition, influenza can also be prevented by vaccination.