Cancer is an uncontrolled growth of the cells in any part of the body. This growth interferes with the way your body normally functions. There are many kinds of cells that make up the tissue in a human body. Cells make new cells by dividing.
Some cells stop dividing when they become adult cells.
Other cells constantly divide, such as those of your skin, hair, and blood. Some divide only if there has been damage somewhere in your body. They eventually crowd out healthy tissues, disrupting your body's ability to do what it needs to do. There are over 100 different kinds of cancer. Many people will get some form of cancer in their lifetime.