Some causes of heavy menstrual bleeding

1. Unexplained - for half of all cases no cause can be found.
   
   
2. Contraceptive coil (IUD) - the coil can cause heavier, longer periods.
   
   
3. Injectable contraception (Depo Provera) - can cause heavy or prolonged bleeding.
   
   
4. Pelvic disorders:
   • Fibroids - these benign (not cancerous) growths in the muscular wall of the uterus are a common cause of heavy bleeding.
   • Polyps - these benign growths of the lining of the uterus may cause heavy bleeding but more commonly lead to spotting between or after periods.
   • Pelvic inflammatory disease - an infection in the reproductive tract which can cause infertility and chronic pain if untreated.
   • Endometriosis - a painful condition in which the lining of the uterus grows outside the uterus.
   • Endometrial hyperplasia - thickening of the lining of the uterus, leading to heavier bleeding.
   • Endometrial cancer - cancer of the lining of the uterus, causing heavy periods, bleeding between periods and blood-stained vaginal discharge. Rare, but more common in women after the menopause.
   
   
   
5. Blood and hormonal conditions:
   • Hormone imbalances - can stop ovulation (egg release) leading to build-up of endometrium and heavier periods.
   • Hypothyroidism - an underactive thyroid gland can cause heavier periods.
   • Blood clotting disorders.
   • Use of anticoagulant drugs.

The menstrual cycle is affected by stress. If you are going through any kind of life crisis, it is possible that your periods may settle down once that crisis has been resolved. Meanwhile reassurance from your doctor that there is nothing seriously wrong may help you to accept this change as a common and usually temporary response to stress. For many women, however, there is no easy solution to the stress in their lives. If this is the case, you will need to decide whether you want treatment for your heavy bleeding.

In all cases, the first step to take is to visit your GP and explain that your periods have changed. Once your doctor and/or gynaecologist have carried out the preliminary tests described in the next section, and you have been given the medical all clear, what happens next will largely depend on how you feel about your heavy bleeding.