What causes womb cancer?

The lining of the womb is called the endometrium. Oestrogen normally works with progesterone to control its growth. When the lining is exposed to oestrogen without enough progesterone for a prolonged time, cells may keep multiplying. This is called unopposed oestrogen exposure.

Endometrial hyperplasia means the lining has become unusually thick because of excess growth. Some forms can develop into cancer, so abnormal bleeding should be assessed. Lynch syndrome, an inherited condition affecting DNA repair, can also raise the chance of womb cancer. Having a risk factor does not mean cancer will develop, and many people have no single identifiable cause.

Arrange a medical assessment for bleeding between periods, unusually heavy periods, bleeding after menopause, or new watery or blood-stained discharge. A clinician may ask about menstrual history, medicines, family history and previous endometrial changes. Tests can include an examination, ultrasound and a sample of the womb lining.

Take a record of bleeding dates, flow and associated pain. Tell the clinician if close relatives have had womb or bowel cancer, or if you have been told you have endometrial hyperplasia. More information is available on [Womb Cancer](/conditions/endometrial-cancer/) and [Endometrial Hyperplasia](/conditions/endometrial-hyperplasia/).

Contact a clinician promptly for any bleeding after menopause or bleeding that is new, persistent or difficult to control. Seek urgent help if bleeding is heavy enough to cause weakness, faintness, breathlessness or soaking through protection repeatedly, or if severe pelvic pain occurs.

Could my bleeding be related to the womb lining? Do I need an endometrial sample or scan? Could a medicine or hormone change be contributing? Does my family history suggest genetic counselling? If hyperplasia is found, what type is it and what follow-up is needed?