Abnormal vaginal bleeding: causes, red flags and what to expect

Doctors begin by classifying the bleeding. Heavy periods, irregular periods, bleeding between periods or after sex, and bleeding after the menopause overlap in some causes but differ in how urgently they are investigated. The age of the person, the possibility of pregnancy, contraception and menopausal stage frame everything.

The NHS notes that heavy periods can be normal for you and can occur when periods first start, after pregnancy or approaching menopause, and that irregular periods are more likely in puberty and when nearing menopause. A change from your own normal pattern is the most useful trigger to seek advice.

• Call 999 or go to A&E for heavy vaginal bleeding with pelvic pain, dizziness or fainting, sudden intense lower tummy pain, a very high temperature or feeling very unwell; the NHS pelvic inflammatory disease page lists pelvic pain with heavy bleeding and these features as emergency signs.

• Call 999 or go to A&E for sudden sharp tummy pain with feeling very dizzy, fainting, sickness and looking very pale if you could be pregnant, which may be a ruptured ectopic pregnancy.

• Contact your GP or NHS 111 the same day if you might be pregnant and have bleeding or brown watery discharge, with low one-sided tummy pain, shoulder-tip pain or discomfort peeing or pooing, even without a positive test.

• See a GP promptly for any bleeding after the menopause, even a small amount or a single episode; the NHS says you need to get it checked.

• See a GP for bleeding between periods or after sex, a change in vaginal discharge, pain during sex, or heavier periods than usual, which the NHS lists as symptoms of cervical and womb cancer, and which most often have other causes.

• See a GP if heavy periods affect your life, are severe and painful, or come with tiredness or shortness of breath, which can signal iron deficiency anaemia.

• Soaking through a pad or tampon every hour for several hours, or passing large clots with dizziness, needs urgent help.

Expect questions about your age, menopausal status, cycle history, how many products you use and for how long, clots, bleeding after sex, pain, discharge, pregnancy possibility, contraception, HRT, medicines including blood thinners and tamoxifen, weight change, thyroid symptoms, cervical screening history, bruising and bleeding elsewhere, and family history of cancer or Lynch syndrome.

The NHS says the GP may ask to examine you, that you can ask for a female doctor or nurse and a chaperone, and that you will be asked to undress from the waist down behind a screen. The GP may feel inside the vagina while pressing on the tummy, and use a speculum to check the cervix as in cervical screening. You are in control and can ask them to stop at any time.

Common first tests are a pregnancy test, a full blood count to look for anaemia, swabs for infection, a cervical screening check if due and, depending on the pattern, thyroid and hormone tests. For heavy periods the NHS notes a series of blood tests may check for conditions such as iron deficiency anaemia.

For postmenopausal bleeding, the NHS says a GP should refer you to hospital or a special postmenopausal bleeding clinic. Tests may include a vaginal ultrasound scan to look at the womb lining, a pelvic and speculum examination, and a hysteroscopy, in which a thin camera is passed through the cervix into the womb, with a biopsy taken for testing under local or general anaesthetic. Similar tests are used if bleeding between periods persists in younger women or if there is a risk factor for womb pathology.

For heavy periods the NHS lists contraception such as an intrauterine system or the combined pill, tranexamic acid to reduce bleeding, and anti-inflammatory painkillers such as mefenamic acid or naproxen, with specialist options including endometrial ablation, removing fibroids or hysterectomy if needed. Irregular periods are treated according to cause: the combined pill for PMOS and medicines for thyroid problems, for example.

Postmenopausal bleeding treatment depends on the cause: the NHS says cervical polyps may be removed, atrophy may need no treatment or oestrogen cream or pessaries, and endometrial hyperplasia may be managed with no treatment, hormone medicine or surgery depending on type. It notes bleeding is not usually serious but can be a sign of cancer, which is easier to treat if found early. Ask the clinician whether your pattern of bleeding fits any of these.