Cancer is a disease that occurs when cells grow and divide too fast. Normal body cells grow and know to stop dividing or to die when they are no longer needed. When cancer cells continue to grow, they can crowd out healthy body cells and destroy them. The cancer cells may also form groups or clumps that grow and spread throughout the body, destroying other tissues and making a person very sick. Cancer can start in any cell. It can grow into a large tumor, which is a group of abnormal cells. It can also break away from the tumor and spread to other parts of the body.
Doctors don’t know exactly what causes most cancers. But they do know that cancer cells develop when genes become damaged or mutated. These mutations can happen in many ways, including from certain types of radiation or from chemicals such as cigarette smoke or sun exposure. Mutations can also happen during normal cell division when a cell copies its DNA so that each new cell gets the same genetic information. If the copied DNA has a mistake, it may cause the cell to grow and divide too rapidly or to make abnormal proteins that can damage the cell or lead to cancer.
A tumor is a collection of cancer cells that grows and forms a lump or mass in the body. A tumor can affect the way a person feels, looks or works. It may be small and not bother a person at all or it can be so large that it prevents them from breathing, swallowing or moving normally. In some cases, the cancer cells spread to other parts of the body through the blood or lymph system. This is called metastasis.
Cancer treatment can help keep the cancer from spreading or returning. It can also reduce a tumor’s size, relieve symptoms and improve a patient’s quality of life. The type of treatment you get depends on the type of cancer and its stage. The higher the stage, the more the cancer has spread and the harder it is to treat.
Healthy lifestyle habits can lower your risk for cancer. A diet rich in fruits and vegetables and low in added sugars and saturated fats can help. Regular physical activity can be helpful, too.