Causes, investigations, and every treatment option — clearly explained.
Heavy periods are one of the most common reasons women see a gynaecologist — and one of the most undertreated. Flooding, clots, fatigue, and iron deficiency are not things you simply have to live with. Here is the full picture.
Heavy Menstrual Bleeding (HMB) is defined as menstrual blood loss that interferes with a woman's physical, emotional, social, or material quality of life. The older objective threshold — 80mL per cycle — is rarely measured in practice. Current guidelines (NICE, ACOG) have moved to a patient-centred definition: if your periods are significantly affecting your life, they qualify as heavy and deserve investigation and management.
HMB affects approximately 1 in 3 women at some point in their reproductive lives. It is the leading cause of iron deficiency anaemia in premenopausal women worldwide. Despite its prevalence, many women normalise their symptoms — often because they have been told "that's just how periods are" — and delay seeking help for years.
There is no medal for suffering through a heavy period. I have sat with women in their late 40s who have been flooding for a decade, become iron deficient, and missed years of work and social life — who were told at each visit that their bloods were "borderline normal" and nothing needed to be done. Heavy bleeding is not a personality trait. It is a symptom. Treat it.
— Dr KD · The Longevity ShiftThe internationally used classification system for abnormal uterine bleeding divides causes into structural (PALM) and non-structural (COEIN):
In many women, particularly in perimenopause, heavy bleeding has more than one cause simultaneously — for example, fibroids plus anovulatory cycles plus iron deficiency that worsens fatigue. Treatment works best when all contributing factors are identified.
Fibroids (uterine leiomyomas) are benign smooth muscle tumours of the uterus. They are the most common benign tumour in women — present in up to 70–80% of women by age 50, though the majority are asymptomatic and never require treatment. They are estrogen and progesterone sensitive, grow during reproductive years, and typically shrink after menopause.
Bulge into the uterine cavity. Most likely to cause heavy bleeding, prolonged periods, and fertility problems. Even small submucosal fibroids can cause significant symptoms. Priority for treatment if symptomatic.
Within the muscle wall. Cause heavy bleeding and bulk symptoms (pelvic pressure, urinary frequency) when large. Smaller intramural fibroids may be incidental findings requiring only observation.
On the outer surface of the uterus. Least likely to cause bleeding. Can cause bulk symptoms, pressure on bladder or bowel. Rarely the primary cause of HMB.
Attached by a stalk, either inside the cavity (submucosal pedunculated) or outside (subserosal pedunculated). Submucosal pedunculated fibroids can prolapse through the cervix and cause acute pain.
The presence of fibroids on ultrasound does not automatically require intervention. Small intramural or subserosal fibroids in an asymptomatic woman can be monitored. Treatment is warranted when fibroids are causing significant bleeding, pain, pressure symptoms, or affecting fertility. The decision is based on symptoms, fibroid location and size, the woman's reproductive plans, and proximity to menopause.
The risk of malignant transformation of a fibroid (leiomyosarcoma) is extremely low — estimated at less than 1 in 1,000, and possibly much lower. Rapid fibroid growth is sometimes cited as a cancer warning sign, but is more commonly simply benign growth in a reproductive-age woman. Leiomyosarcoma is a rare, distinct tumour — it is not a fibroid that has "turned cancerous."
Adenomyosis occurs when endometrial glands and stroma (the tissue that normally lines the uterine cavity) grow into the myometrium — the muscular wall of the uterus. Each month, this ectopic tissue responds to hormonal cycling: it bleeds, causing inflammation and fibrosis within the muscle wall. The result is a uterus that is enlarged, boggy, and painful — and periods that are heavy, prolonged, and cramping.
Adenomyosis was historically only diagnosed definitively by histology after hysterectomy. Modern high-resolution transvaginal ultrasound can now diagnose adenomyosis non-invasively with sensitivity and specificity over 80% in experienced hands. MRI provides additional detail when the ultrasound picture is uncertain. Key ultrasound features include: heterogeneous myometrium, myometrial cysts, asymmetric thickening of the uterine walls, and poorly defined junctional zone.
Despite improved diagnostics, the average time from symptom onset to diagnosis remains 6–9 years — largely because heavy painful periods are normalised rather than investigated.
Adenomyosis is not rare — it is under-diagnosed. It sits at the intersection of heavy bleeding, pain, and fertility problems, and yet it is frequently absent from the explanation women are given for their symptoms. If you have heavy, painful periods and a bulky uterus on ultrasound, adenomyosis belongs in the differential. Push for it to be considered.
— Dr KD · The Longevity ShiftEndometrial polyps are localised overgrowths of the endometrial glands and stroma, attached to the uterine lining by a stalk (pedunculated) or a broad base (sessile). They range from a few millimetres to several centimetres. They are estrogen-sensitive and more common in women in their 40s and 50s, in women with obesity, and in women using tamoxifen.
Polyps cause irregular bleeding, intermenstrual spotting, postcoital bleeding, and heavy periods. The bleeding is often irregular and unpredictable — different from the heavy but cyclic bleeding of fibroids or adenomyosis. Even small polyps can cause significant irregular bleeding. They are also associated with impaired embryo implantation and are a treatable cause of subfertility.
Transvaginal ultrasound detects polyps, particularly when performed in the early follicular phase when the endometrium is thin. Saline infusion sonography (SIS) or HyCoSy improves detection by outlining the cavity with fluid. Hysteroscopy — direct visualisation of the uterine cavity — is the gold standard for diagnosis and allows simultaneous polypectomy (removal) under direct vision.
Polypectomy is a day procedure, usually performed under local anaesthetic or light sedation. Most women can return to normal activity the same day.
The vast majority of endometrial polyps are benign. Malignant transformation is rare — approximately 0.5–1% overall, rising to 3–4% in postmenopausal women with bleeding. All polyps removed at hysteroscopy should be sent for histological analysis. Postmenopausal women with polyps and bleeding should have polyps removed and examined — the risk of malignancy in this group is not negligible.
In perimenopause, ovulation becomes irregular and eventually ceases. Without ovulation, the corpus luteum is not formed and progesterone is not produced. Unopposed estrogen stimulates the endometrium to proliferate unchecked — producing an unstable, thickened lining that sheds irregularly and heavily. This is one of the most common causes of heavy and unpredictable bleeding in women in their 40s, and is frequently treated with progestogen supplementation or the Mirena IUD.
Both hypothyroidism and hyperthyroidism can disrupt the menstrual cycle. Hypothyroidism is particularly associated with heavy and prolonged periods — thyroid hormone deficiency impairs the coagulation cascade and prolongs bleeding time. It is also a common co-diagnosis with other gynaecological causes. TSH should be checked in every woman presenting with heavy periods. Treating the thyroid abnormality often significantly improves bleeding.
Von Willebrand disease (vWD) is the most common inherited bleeding disorder, affecting approximately 1% of the population. Because women with vWD bleed heavily from their first period, many assume this is normal — and are never diagnosed. vWD should be considered in any woman with HMB since menarche, easy bruising, prolonged bleeding from cuts or dental procedures, or family history of bleeding disorders. Screening requires specialised coagulation testing beyond a standard FBC and clotting screen.
Menstrual blood contains 0.5–1mg of iron per mL. A normal period involves approximately 30–40mL of blood loss — manageable with a normal diet. Heavy periods can involve 150–300mL or more per cycle. At this rate, dietary iron intake — even optimised — cannot keep pace with losses. Iron deficiency develops slowly but progressively, often over years, with symptoms so gradual that many women normalise them completely.
Iron deficiency (low ferritin, normal haemoglobin) causes fatigue, brain fog, hair loss, cold intolerance, poor exercise tolerance, and reduced immunity — even before anaemia develops. A normal full blood count does not exclude iron deficiency. Ferritin must be checked separately. A ferritin below 30 µg/L is functionally deficient even if haemoglobin is normal. Many women are told their bloods are fine when their ferritin is 12.
Iron deficiency worsens fatigue, reduces exercise tolerance, and impairs cognitive function — but it also impairs platelet function and coagulation, which can worsen the very bleeding causing the deficiency. Treating iron deficiency is not an alternative to treating the underlying cause of HMB — both must be addressed simultaneously.
Target ferritin for women with HMB is ≥50 µg/L — not the laboratory lower reference range of 10–15. A ferritin of 15 is technically "within range" but is not a replete iron store. Do not accept borderline ferritin as normal if you are symptomatic.
The first-line imaging investigation for HMB. Assesses uterine size and shape, myometrial texture (adenomyosis features), fibroid number, location, and size, endometrial thickness and appearance, and ovarian pathology. Performed ideally in the early follicular phase (days 4–8) when the endometrium is thin and polyps are most visible. A normal TVUS does not exclude all pathology — small polyps and early adenomyosis can be missed.
Instilling saline into the uterine cavity during ultrasound outlines the endometrium and significantly improves detection of polyps and submucosal fibroids. A relatively simple outpatient procedure that provides far more detail than standard TVUS for intrauterine pathology.
Direct visualisation of the uterine cavity with a thin camera. The gold standard for diagnosing and treating intrauterine pathology. Can be performed as an outpatient procedure (office hysteroscopy) under local anaesthetic or as a day surgical procedure. Allows simultaneous polypectomy, biopsy, or removal of submucosal fibroids. Any woman with persistent HMB, abnormal bleeding pattern, or ultrasound abnormality should be considered for hysteroscopy.
A small sample of endometrial tissue taken in clinic to exclude endometrial hyperplasia or malignancy. Indicated in: women over 45 with HMB, any woman with risk factors for endometrial cancer (obesity, PCOS, diabetes, tamoxifen use, family history of Lynch syndrome), postmenopausal bleeding, or an abnormally thick endometrium on ultrasound.
Tranexamic acid is an antifibrinolytic — it stabilises blood clots by inhibiting plasminogen. Taken during the period (not continuously), it reduces menstrual blood loss by approximately 40–50%. It does not affect the hormonal cycle, ovulation, or fertility. It is suitable for women who want to avoid hormonal treatment or are trying to conceive. It treats the symptom without addressing the underlying cause. Side effects are mild (nausea in some); rare risk of thrombosis means it is avoided in women with clotting disorders or high VTE risk.
NSAIDs reduce prostaglandin production — reducing both bleeding (by ~25–30%) and dysmenorrhoea simultaneously. Taken from the day before or the start of the period. Best suited for women with both heavy bleeding and significant period pain. Less effective than tranexamic acid for bleeding alone, but the dual effect on pain makes them a useful first-line option for many women.
Oral norethisterone (5mg three times daily from days 5–26, or continuously) suppresses endometrial proliferation. Effective for anovulatory HMB and as a temporary bridge to other treatments. Does not provide contraception at standard doses. Not ideal long-term due to androgenic side effects (acne, mood changes, weight gain) in some women. Being largely superseded by the Mirena for ongoing management.
The COCP reduces blood loss by 40–70%, regulates cycles, reduces dysmenorrhoea, and provides contraception — a useful combination for many women with HMB. Can be taken continuously (no pill-free interval) to eliminate periods entirely. Contraindicated in women with migraines with aura, high VTE risk, smokers over 35, or hypertension. Not suitable for perimenopausal women with cardiovascular risk factors.
Create a temporary medical menopause by down-regulating the HPO axis — periods stop completely within 1–2 months. Highly effective short-term. Used as a bridge before surgery (to correct anaemia, shrink fibroids), or temporarily in adenomyosis. Limited to 6 months without add-back HRT due to bone density loss. Not a long-term solution independently.
The Mirena is a levonorgestrel-releasing intrauterine system (LNG-IUS) — a small T-shaped device placed inside the uterus that releases a low dose of levonorgestrel (a progestogen) locally into the endometrium. It thins the endometrial lining dramatically, reducing menstrual blood loss by 70–95% and eliminating periods entirely in approximately 20–30% of users by 12 months. It lasts 5–8 years and provides highly effective contraception simultaneously.
Head-to-head trials comparing the Mirena to oral medication for HMB consistently show it is more effective, with better quality of life outcomes and higher user satisfaction. The NICE guidelines for HMB list the Mirena as the first-line treatment where long-term management is needed and the woman does not want immediate surgery. It is also cost-effective — one device for 5–8 years vs ongoing medication costs.
The Mirena is particularly effective in adenomyosis — it directly suppresses the ectopic endometrial tissue within the myometrium as well as the cavity lining. In women with fibroids, it is most effective when fibroids are not distorting the uterine cavity (submucosal fibroids may prevent proper placement or reduce efficacy). It is not a treatment for the fibroids themselves, but it manages the bleeding they cause.
The Mirena is one of the most underutilised tools in gynaecology. I have seen women undergo hysterectomy for heavy periods without ever having tried a Mirena. It is not suitable for every woman — but for the majority with HMB who want a long-term, reliable, non-surgical solution, it deserves to be the starting point, not an afterthought.
— Dr KD · The Longevity ShiftEndometrial ablation destroys the uterine lining using heat (radiofrequency, microwave, balloon thermal) or cold (cryoablation). It is a day procedure, usually performed hysteroscopically under sedation or general anaesthetic. It reduces bleeding by 80–90% and eliminates periods in approximately 30–40% of women. It is not suitable for women who want to preserve fertility — pregnancy after ablation is possible but dangerous. It is not effective in the presence of significant adenomyosis (the disease is in the muscle, not the lining) or large submucosal fibroids. Success rates are lower in younger women.
Myomectomy removes fibroids while preserving the uterus. The preferred approach for women with symptomatic fibroids who wish to retain fertility or their uterus. Routes include:
Fibroids can recur after myomectomy — cumulative recurrence rates are approximately 20–30% at 5 years. Women nearing menopause have lower recurrence risk.
Hysterectomy (surgical removal of the uterus) is the only treatment that permanently eliminates periods and is the most definitive treatment for HMB. It is appropriate when: medical management has failed or is not tolerated; the woman has completed her family; quality of life is significantly and persistently impaired; there is co-existing pathology (e.g., severe adenomyosis, large symptomatic fibroids) not amenable to uterine-preserving surgery. Modern hysterectomy is predominantly laparoscopic — a 1–2 night hospital stay with 2–4 week recovery — rather than the open procedure of previous decades.
Hysterectomy should never be a first-line treatment for HMB — but it should never be indefinitely withheld from a woman whose quality of life is severely affected and who has failed or declined uterine-preserving options. It is not a last resort. It is a legitimate, well-evidenced choice with very high patient satisfaction rates.
Endometrial cancer is the most common gynaecological cancer in developed countries. It is predominantly a disease of postmenopausal women — the average age at diagnosis is 63. However, it does occur in premenopausal women, particularly those with significant risk factors. The good news: most endometrial cancer presents early (stage I) with abnormal bleeding, and early-stage endometrial cancer has a 5-year survival rate of over 90%.
Transvaginal ultrasound first (endometrial thickness and appearance). If the endometrium is thickened, irregular, or if clinical suspicion is high regardless of ultrasound: endometrial biopsy (Pipelle sampling in clinic) and/or hysteroscopy with biopsy. A normal Pipelle biopsy does not absolutely exclude cancer if clinical suspicion remains — hysteroscopy with directed biopsy is more sensitive.
Postmenopausal bleeding is endometrial cancer until proven otherwise. It should never be attributed to "a bit of dryness" or dismissed without imaging and, where indicated, biopsy. Reassurance without investigation is not acceptable clinical practice.