Heavy periods

Heavy menstrual bleeding is defined by volume rather than a feeling, and a useful threshold is soaking through protection in an hour, passing clots larger than a coin, needing double protection, or bleeding that limits normal activity. Many women considerably underestimate their own loss.

The cause matters, and some causes matter a lot. Fibroids, adenomyosis, endometrial polyps, endometriosis, thyroid disease, a bleeding disorder (including von Willebrand disease, which is not rare in women with heavy periods since childhood), and — the reason assessment is not optional — endometrial hyperplasia and endometrial cancer. Heavy bleeding in a woman over 45, or with irregular bleeding, needs assessment including endometrial sampling, because the risk of hyperplasia and cancer rises.

Iron deficiency is the immediate consequence and it is very commonly missed. Heavy periods are the commonest cause of iron deficiency in menstruating women, and a woman can be iron deficient with a normal haemoglobin — ferritin is the test. Get the ferritin checked; the symptoms of iron deficiency (fatigue, breathlessness, hair loss, restless legs, brain fog) are often attributed to the periods themselves.

The treatments with evidence. The levonorgestrel intrauterine system, which reduces bleeding substantially and is first-line for many women; tranexamic acid, taken during the period and effective; NSAIDs, which reduce bleeding by around 30%; combined hormonal contraception; progestins; and surgical options including endometrial ablation and hysterectomy for refractory cases. This is a clinical decision.

What has weak evidence. Herbal preparations for heavy bleeding, including some traditional astringents. Where a specific cause exists — a fibroid, hyperplasia, a bleeding disorder — a herb is a delay and the treatment is medical or surgical.

Iron supplementation alongside. If the periods cannot be reduced immediately, iron is needed, and it should be taken according to the absorption rules on the iron page — alternate-day dosing, with vitamin C, away from tea and calcium. Do not accept "just take iron" as the whole answer: the bleeding is the source and it needs treating.