Staying up late is bad for the body, mainly including causing cardiovascular and cerebrovascular diseases, endocrine disorders, and decreased immunity. Smoking is bad for the body, mainly including affecting respiratory function, and even inducing cancer. Therefore, it is recommended to avoid staying up late and smoking, maintain good habits to promote their own health. First, stay up late: 1, cardiovascular and cerebrovascular diseases: long-term stay up late crowd, the length of its sleep is not enough, can lead to long-term fatigue state of the body, resulting in depression, elevated blood pressure. If the situation is more serious, it can affect the heart and blood vessel function, and even cause sudden death; 2, endocrine disorders: maintain a good work and rest, the body can regularly secrete the relevant hormones to maintain a normal state. However, when staying up late, the body’s hormone secretion will be disrupted, which can show acne, loss of appetite, some women can show symptoms such as menstrual disorders; 3, decreased immunity: the body is in a state of long-term fatigue, endocrine dysfunction at the same time, which can lead to a gradual decline in the immune function of the body, which is easy to infected with viruses, bacteria and other pathogens, resulting in the emergence of related diseases such as influenza and so on. Smoking: 1, affecting respiratory function: after burning cigarettes, irritating gases can be released to stimulate the respiratory tract, causing coughing, sneezing and other symptoms, affecting the normal respiratory function; 2, carcinogenic: tobacco contains a variety of carcinogenic substances, such as coal tar, nitrosamines, polycyclic aromatic hydrocarbons, benzene, etc. These harmful substances not only increase the lung cancer rate, but also increase the risk of lung cancer, which can lead to the development of lung cancer. These harmful substances not only increase the risk of lung cancer, but also induce the risk of laryngeal cancer, liver cancer, etc.; 3. Other: If pregnant women have the habit of smoking, it may have an impact on the growth and development of the fetus. Children who have the habit of smoking may lead to abnormal development.