My 72 year old mother just started bleeding vaginally. she has mild cramping pain also. what is this?

See the Gyn doc ASAP: Postmenopausal bleeding is worrisome because it may be a sign of endometrial hyperplasia (overgrowth of the uterine lining which can lead to cancer) or endometrial cancer. The bleeding may also be from the vaginal wall or the rectum. She needs an exam to determine the exact source. If it is from the uterus, she'll need a biopsy to rule out cancer.