Causes of heavy bleeding during a period

Fibroids, adenomyosis and endometrial polyps can increase bleeding by changing the uterus or its lining. Irregular ovulation, including during perimenopause or with polycystic ovary syndrome, may allow the lining to build up before it sheds.

Bleeding deserves assessment when it is clearly heavier than your usual pattern, repeatedly soaks through period protection, requires changes during the night, includes large clots, or interferes with sleep and daily activity. The pattern matters as much as the amount: bleeding between periods, after sex, or after menopause is not simply a heavy period.

Ongoing blood loss can deplete iron. Iron-deficiency anaemia may present with unusual tiredness, weakness, breathlessness, paleness, headaches or a racing heartbeat.

Keep a record of when bleeding starts and stops, how often you change pads, tampons or menstrual products, whether flooding or clots occur, and any pelvic pain or bleeding outside the period. Note medicines and contraception, especially blood-thinning treatment or a recently fitted intrauterine device.

Arrange a clinical review if the change persists or affects your routine. Assessment may include a pregnancy test when relevant, a blood count and iron tests, examination, and pelvic imaging. Treatment is selected according to the cause, your other health conditions, and whether you hope to become pregnant.

Seek urgent medical help for very heavy or rapidly increasing bleeding with fainting, marked dizziness, difficulty breathing, chest pain, confusion, severe weakness or a fast heartbeat. These features can signal significant blood loss.

Urgent assessment is also needed for heavy bleeding with severe pelvic pain, fever, a positive pregnancy test, or a possibility of pregnancy. New bleeding after menopause should be assessed promptly even when it is light.

Ask which causes fit your bleeding pattern, whether you need blood tests or an ultrasound, and whether your medicines could be contributing. You can also discuss options that reduce bleeding, possible side effects, how treatment relates to contraception or fertility, and when follow-up is needed.