Cancer is a disease in which some of the body’s cells grow uncontrollably and spread to other parts of the body. Cancer can start almost anywhere in the human body, which is made up of trillions of cells. Normally, human cells grow and divide to form new cells as the body needs them. When old cells die, they are naturally replaced. However, cancer disrupts this process. Cancer cells continue to grow and divide even when new cells are not needed. They can also invade other tissues and organs, damaging them and interfering with their function.
There are many different types of cancer, and each type can behave differently. Some cancers grow slowly and may not cause symptoms for years, while others grow quickly and spread to other parts of the body right away.