A cold or fever is also called an upper respiratory tract infection, and blood is drawn mainly for routine blood and biochemical tests. A cold or fever caused by bacterial infection may have elevated blood picture, that is, elevated white blood cells and neutrophils. In addition, prolonged fever can cause abnormal liver function, with elevated transaminases and elevated bilirubin. Blood tests are used to understand the occurrence and development of the disease, and anti-cold medications are used in a timely manner. Commonly used cold granules and capsules, such as cold and fever granules, Lianhua Qingfei capsule, and anti-viral oral liquid, should drink more water and pay more attention to rest during treatment.