Certain diseases or states provide favorable conditions for the onset of tuberculosis, and therefore these diseases often accompany tuberculosis and are called coexisting diseases. In recent years, there has been an increase in the incidence of AIDS, diabetes, asthma, etc., and the incidence of tuberculosis, so the prevention and treatment of these diseases should be strengthened. AIDS: HIV infection reduces the body’s cellular immunity, making the human body susceptible to TB infection and disease, and easy to spread and die, and currently up to 1/3 of AIDS patients in Africa have TB, and the incidence is 3-6 times that of HIV-negative patients. Diabetes: its metabolic abnormalities lead to reduced resistance, as well as metabolic products conducive to the growth of tuberculosis bacteria is the basis for easy infection prone to tuberculosis. The prevalence of diabetes mellitus in China is 19.3%-24.1%, which is 4-8 times higher than that of the general population, and there is an increasing trend. However, the prevalence of diabetes has increased in China over the past decade or so, and the complication rate between the two has even doubled. Asthma: It has been found that tuberculosis is 5 times more common in people with asthma than in healthy people. The reasons for this may be: (1) tuberculosis bacteria directly damage the bronchial tubes, and its metabolites can make the bronchial tubes more reactive; (2) tuberculosis can be secondary to viral infection induced asthma; (3) anti-tuberculosis drugs lead to allergic reactions, the incidence of which is reported to be about 1.5%. Silicosis: Because silica dust impairs phagocytosis and affects peripheral cells, it interferes with lymphokine production and therefore affects immune function and predisposes to tuberculosis. TB patients are also susceptible to silicosis due to reduced clearance of dust from the respiratory tract. The complication rate of both is quite high. Tuberculosis in stage I and II silicosis accounts for 20-40% of cases, while in stage III cases it can reach 70-95%.