Besides common diseases which are curable there is cancer, a disease known to the medical world for a long time. It is still a malignant disease for which an assured cure has not been found. Throat cancer, cancer of the lung, bone and breast are the most common types of this disease. The most common cause of cancer is the use of tobacco either by chewing or smoking this deadly leaf. These cause throat cancer and lung cancer. The incidence of throat cancer in the world is the highest in Mainpuri district in Uttar Pradesh where people chew too much of tobacco. The statutory warning on cigarette packs has stopped neither smoking nor cancer.

In India near about 3 per cent people suffer from cancer. Although the percentage seems small it comes to 1.75 million. Cancer is the fourth sign of the Zodiac in astronomy. Its symbol is crab. In the beginning a cell becomes cancerous, if it is detected it can be done away with. Tata Cancer Institute, Mumbai gives almost hundred per cent surety about the cure. But if it is not detected in the beginning it spreads like the clutch of a crab. The cancerous cells can be killed by Radio Therapy. But if they spread in the body chemo-therapy treatment is given. It is generally the last stage and the patient is rarely saved. The survival rate is insignificant. The life of a cancer patient from the date of detection is generally five years.

The other incurable disease that was known to the medical world in the USA in 1981 is AIDS i.e. Acquired Immune Deficiency Syndrome. It is considered a viral disease which totally kills the immunity system. The body cannot resist the attack of any disease. The patient gradually loses strength and meets the inevitable death generally within two years.

Although no scientific cause has been known there is a widespread belief that the AIDS virus is a gift of homosexual male relations. If it is so it is rather a bane of the promiscuous culture of the West. Thousands of people die of AIDS in USA alone. It is an Infectious disease transmitted through sexual contacts, transmission of blood of an AIDS patient and is acquired by the child born of an AIDS mother. It has already entered India. If precautions are not taken it may take an epidemic form as the people suffering from it feel shy of reporting to a government health centre or hospital. The virus has been isolated. But it may not be killed through vaccine as it changes its structure every now and then. After nuclear weapons AIDS may prove the greatest killer in the world.