Treatment Doctors may prescribe drugs to help the body fight infection and repair damaged tissues. Drugs are made from natural substances such as plants, or synthetically from chemicals, and are classified accord-ing to their effect on the body. There are drugs to fight bacteria, prevent infectious diseases, affect the heart and the bloodstream, or affect the nervous system and so on. If the best treatment involves surgery, the patient will go into hospital to have the damaged or diseased parts removed or repaired. Transplant surgery is now available, in which entire organs can be replaced.
Laser surgery uses an intense beam of light to cut or repair tissue.
Nuclear medicine, which uses radioactive materials, is used in both diagnosis and treatment. Radiotherapy is often used to treat cancer. While patients are in a critical condition they are given intensive care, where the combined use of drugs, life-support machines and accurate monitoring systems may enable them to start a good recovery. For thousands of years people have known about the healing properties of certain plants, but primitive surgery lost more lives than it saved. Until the l6th century, knowledge of human anatomy was inaccurate and there was a high risk of infection.