In general, tumors appear to occur when there is a problem with the dividing of cells in the body. Typically, the division of cells in the body is strictly controlled. New cells are created to replace older ones or to perform new functions. Cells that are damaged or no longer needed die to make room for healthy replacements.
If the balance of cell division and death is disturbed, a tumor may form.
Problems with the body's immune system can lead to tumors. Tobacco causes more deaths from cancer than any other environmental substance. Other causes include:
Some tumors are more common in one gender than the other. Some are more common among children or the elderly. Others vary with diet, environment, and your family history.
Symptoms
Symptoms depend on the type and location of the tumor. For example, lung tumors may cause coughing, shortness of breath, or chest pain, while tumors of the colon can cause weight loss, diarrhea, constipation, iron deficiency anemia, and blood in the stool.
Some tumors produce no symptoms, but symptoms that may occur with tumors include:
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc., 08/03/2008
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