Heavy Periods in Adolescence – What’s Normal and When to Get Help
Why Heavy Periods Matter
Heavy periods — also called heavy menstrual bleeding (HMB) — are more than just an inconvenience. For teenagers, they can mean missed school, fatigue, low mood, and anxiety about leaking. The World Health Organization and UK Women’s Health Strategy have highlighted menstrual health as a major issue because of its impact on education and confidence.
NICE defines heavy bleeding as flow that lasts longer than 7 days, requires changing pads/tampons every 1–2 hours, or disrupts daily life. If this sounds familiar, it’s important to know you’re not alone — and that support and treatments are available.
Common Causes in Teenagers
Anovulatory cycles: In the first years after starting periods, ovulation is often irregular because the hormonal system (the hypothalamic–pituitary–ovarian axis) is still maturing. This is the most common cause of heavy bleeding in teenagers and usually improves with time.
Bleeding disorders: Conditions like von Willebrand disease can show up first as very heavy periods. Sometimes there’s a family history of easy bruising or nosebleeds too.
Hormonal or endocrine conditions: Hypothyroidism or polycystic ovary syndrome (PCOS) may contribute.
Other causes: Endometriosis, connective tissue disorders (e.g. Ehlers–Danlos syndrome), chronic illness, or certain medications (like anti-epileptics) can also play a role.
What Can Help
Treatment depends on the cause, severity, and personal preferences. Options include:
Simple measures: Keeping a period diary (on paper or an app), iron supplements if anaemia develops, and lifestyle support.
Non-hormonal medicines: Tranexamic acid (reduces bleeding by nearly half) and NSAIDs like ibuprofen can be effective.
Hormonal options:
Combined oral contraceptives (COCP), patches, or rings – can regulate cycles and lighten flow.
Progestogen-only pills or injections – useful if oestrogen is unsuitable.
The levonorgestrel intrauterine system (LNG-IUS, e.g. Mirena®) – very effective at reducing bleeding, though fitting may need a specialist.
In urgent cases where bleeding is very heavy, higher-dose hormonal therapy or hospital treatment may be needed, but this is rare.
When to See a Doctor
Make an appointment if:
You’re changing pads/tampons every 1–2 hours.
Periods last longer than 7 days most cycles.
You feel dizzy, exhausted, or look pale (signs of anaemia).
You have a family history of bleeding problems.
Your periods affect school, sports, or social life.
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Yes. Many girls have irregular or heavy cycles at first because the body hasn’t settled into regular ovulation. This often improves with time.
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Yes. They can lead to iron deficiency or anaemia, which causes tiredness, poor concentration, and low mood.
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Not always. Many teens can start treatment without invasive tests, but doctors may check blood counts, iron levels, thyroid function, or clotting if symptoms are severe.
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Most hormonal contraceptives and non-hormonal medicines can be used safely in adolescents, depending on personal health factors.
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Yes. Some treatments, like continuous hormonal contraception or the LNG-IUS, can safely stop periods altogether if that’s preferred.