Cancer is a disease of the cells. Cancers are of different types but all of them originate with one abnormal cell. When the genes that control the way cell divide and multiply are altered or damaged, the cells become abnormal and if this cell survives, it can multiply, forming a malignant tumour.

The causes of cancer are many and some of them are given here. Chemical carcinogens cal damage cells and make it a cancerous cell. Tobacco is also one of the major causes of cancer across the globe. Age is also one of the factors that may contribute to the development of cancer. Certain lifestyle related causes are also there like eating food with less fibre and vitamins and minerals. Exposure to radiation can also cause cancer. Weak immune system can also contribute to the development of cancer.Some cancers are also caused by infection.