The most common known cause of heavy bleeding is the presence of fibroids in the womb.
Fibroids are non-cancerous growths made of bundles of muscle fibres that grow in the muscle wall of the womb. They can grow in different parts of the womb.
Fibroids just under the lining of the womb are more likely to cause problems because they increase the surface area that is shed every month during a period. Even small fibroids here can increase the amount of bleeding.
You have several choices: no treatment; tablets, a hysterectomy or myomectomy (an operation to remove the fibroid). Your decision will depend on how you feel about your heavy bleeding rather than on the fact that you have fibroids. If you are found to have fibroids the doctor will explain the options available to you in greater detail.