A tumor is a mass of tissue that’s formed by an accumulation of abnormal cells. Normally, the cells in your body age, die, and are replaced by new cells. With cancer and other tumors, something disrupts this cycle. Tumor cells grow, even though the body does not need them, and unlike normal old cells, they don’t die. As this process goes on, the tumor continues to grow as more and more cells are added to the mass. Brain tumors emerge from the various cells that make up the brain and central nervous system and are named for the kind of cell in which they first form.
Symptoms of brain tumors vary according to the type of tumor and the location. Because different areas of the brain control different functions of the body, where the tumor lies affects the way symptoms are manifested. Some tumors have no symptoms until they are quite large and then cause a serious rapid decline in health. Other tumors may have symptoms that develop slowly. A common initial symptom of a brain tumor is headaches.