Medicine is the science of treating illnesses and preserving the body in full health. In olden times, the medical system was a combination of spiritualism, herbal treatment and the conventional treatment followed in each geographic area. Modern medicine is based on solid research, tests and evidence. The doctors depend on medications, surgeries and other modern techniques for curing illness. In the system of modern medicine, the physician, based on the symptoms and observations along with his own clinical judgement and experience, arrives at a diagnosis. Physical examinations of the patient and laboratory investigations reveal the exact state of the patient. The specialized doctors interact with each other to ensure that the patient receives proper care.