Although medicine is developed, there are still more and more patients. This is because people's living environment is increasingly unsatisfactory. In terms of natural environment, water quality, soil and air are getting worse and worse, and some harmful pollutants are treated at will, laying hidden dangers. The food that people eat is not safe enough, which makes people eat something wrong. Pesticides exceed the standard, additives are randomly added to food, fake and shoddy food, etc. Buried a time bomb on people. Bad lifestyle is also one of the reasons for the increasing number of patients. For example, smoking and drinking are pathogenic and fatal factors. For example, eating big fish and meat, eating barbecue and eating foreign fast food are all unscientific. For another example, if you watch mobile phones and play games for a long time and your eyes are exposed to the sun for a long time, these people will have more chances to suffer from various eye diseases (cataract, glaucoma, macular degeneration, etc.). With the improvement of living standards, people's life expectancy is relatively prolonged, but senile diseases are also increasing accordingly. Many people have lived with illness for a long time, and their quality of life is not satisfactory. This is also one of the reasons for the increasing number of patients. So how to reduce human diseases from the perspective of science and medicine? First of all, people should have certain medical knowledge. For example, know the dangers of smoking and drinking, and know the knowledge and methods to prevent hypertension, diabetes and cardiovascular and cerebrovascular diseases. Secondly, improve the living environment and living environment. For example, pollutant treatment should be scientific, water resources should be protected, and harmful materials should not be used in home decoration. Thirdly, reasonable diet, moderate exercise and so on. Diet must be scientific and reasonable. Don't eat unsanitary food, contaminated food and harmful food. Eat a variety of foods, enough is enough. Moderate exercise, excessive exercise is not good, and some athletes exercise excessively, leaving many problems. In short, people can reduce the chance of getting sick and live a long and healthy life by developing a correct lifestyle, eating scientifically and reasonably, exercising moderately, and reducing contact with the environment that is harmful to health. Some healthy and long-lived old people set an example for future generations.