Brain tumors are caused by masses that form inside the brain. Cells in our body are constantly growing and replacing old existing cells with new ones. In brain tumors, brain cells begin to grow and divide in an uncontrolled manner. which is not normally recognized by the body. This rapid cell proliferation is different from the normal cell response. This increases the chances of the cells becoming cancerous in the long run. Rapidly multiplying brain cells slowly begin to destroy healthy brain cells, and the proliferation of abnormally dividing cells is known to be a primary cause.