Patient Basics: Abnormal Uterine Bleeding (Dysfunctional Uterine Bleeding)

Dysfunctional uterine bleeding is an older name for bleeding from the uterus (womb) that is heavier, longer, more frequent or less regular than a normal period, when no growth or disease explains it. Today doctors group all of these problems as abnormal uterine bleeding and look for the cause, which is often an ovary that isn’t releasing an egg each month. Abnormal bleeding is common, and many treatments work. Heavy bleeding can cause anemia (low iron in the blood), so it’s worth getting checked rather than putting up with it.

Key points

• A typical period comes every 24 to 38 days and lasts up to 8 days.
• Common causes include skipped ovulation, fibroids, polyps, thyroid problems and bleeding disorders.
• Pregnancy is checked first, because bleeding in pregnancy needs its own care.
• Treatments range from pills taken only during your period to a hormone IUD, and procedures if medicine doesn’t help.
• Any bleeding after menopause needs a doctor’s visit.

What counts as abnormal

Periods vary from person to person, so the change from your usual pattern matters. Talk with a doctor if you have:

• Bleeding that soaks a pad or tampon every hour or two, or needs a change during the night
• Clots larger than a quarter
• Periods that last more than 8 days
• Periods less than 24 days apart, or more than 38 days apart
• Cycle lengths that swing a lot from month to month
• Bleeding or spotting between periods or after sex
• Any bleeding after menopause (a full year with no period)

What causes it

Hormone causes

Each month, the ovary normally releases an egg (ovulation) and then makes progesterone. Progesterone keeps the lining of the uterus stable and lets it shed in an orderly way. When ovulation doesn’t happen, the lining keeps thickening under estrogen alone and becomes unstable. It then sheds unevenly, which can cause skipped periods followed by heavy, long bleeding. This bleeding from skipped ovulation (anovulatory bleeding) was the main meaning of dysfunctional uterine bleeding.

Ovulation often skips:

• In the first few years after periods start
• In the years before menopause (perimenopause)
• With polycystic ovary syndrome (PCOS)
• With thyroid disease or a high level of the hormone prolactin
• With obesity, big weight changes, intense exercise or major stress

Growths and other causes

• Fibroids, noncancerous muscle growths in the wall of the uterus
• Polyps, small soft growths on the lining
• Adenomyosis, where lining tissue grows into the muscle wall, often causing heavy, painful periods
• Bleeding disorders such as von Willebrand disease, which often cause heavy periods from the very first one
• Medicines, including blood thinners, some hormone birth control and some antidepressants
• Infection of the cervix or uterus, sometimes from a sexually transmitted infection
• Precancer or cancer of the uterine lining, which becomes more likely after age 45 and after menopause

How it’s diagnosed

Your doctor will ask about your periods, how much you bleed, your birth control and medicines, and whether family members bleed easily. Keeping a record of your bleeding days and how many pads or tampons you use helps. Expect a pelvic exam and some of these tests:

• A pregnancy test
• A blood count and iron level, to check for anemia
• Thyroid and other hormone tests
• Tests for a bleeding disorder, if your periods have always been heavy
• Tests for infection, and a Pap or HPV test if you’re due
• A pelvic ultrasound, usually with a slim probe placed in the vagina, to look for fibroids, polyps or a thick lining
• An endometrial biopsy, where a thin tube takes a small sample of the lining. This is usually done for women 45 and older, or younger women with risk factors such as obesity or PCOS.

Sometimes a doctor looks inside the uterus with a thin lighted scope passed through the cervix (hysteroscopy). Small polyps can often be removed during the same procedure.

How dysfunctional uterine bleeding is treated

The right choice depends on the cause, how heavy the bleeding is, your age and whether you want to get pregnant.

Medicines

• Anti-inflammatory pain relievers such as ibuprofen or naproxen, taken during your period, can reduce blood loss and cramps.
• Tranexamic acid is a pill taken only on heavy days. It helps blood clot and can cut flow a lot.
• The hormone IUD (levonorgestrel) releases a progestin inside the uterus. It is one of the most effective treatments for heavy periods, and many users have very light periods or none at all.
• Birth control pills, the patch or the ring make cycles regular and periods lighter.
• Progestin pills or shots help when bleeding comes from skipped ovulation.
• Other hormone medicines that lower estrogen for a time can shrink fibroids and reduce bleeding.
• Iron pills or infusions treat anemia.

Procedures

• Removing polyps or some fibroids through a scope or with surgery (myomectomy), keeping the uterus in place
• Uterine artery embolization, which blocks the blood supply to fibroids so they shrink
• Endometrial ablation, which destroys the lining of the uterus. It is only for women who don’t want future pregnancies.
• Hysterectomy, removing the uterus. This ends periods for good and is usually kept for when other treatments haven’t worked.

Very heavy bleeding

Sudden, very heavy bleeding may be treated in the hospital with hormones or tranexamic acid through a vein, a blood transfusion, or a procedure to remove the lining (dilation and curettage, or D&C).

Living with it

• Track your periods in a notebook or app so you can spot changes and show your doctor.
• Eat iron-rich foods such as beans, leafy greens, lean meat and iron-fortified cereal, and ask whether you need an iron pill.

When to see a doctor

• Any of the changes listed under “What counts as abnormal”
• Tiredness, shortness of breath or a pale look, which can mean anemia
• Bleeding while you could be pregnant
• Any bleeding or spotting after menopause

Get emergency care if you soak through a pad or tampon every hour for 2 hours or more, feel dizzy or faint, have a racing heart or chest pain, or have heavy bleeding with belly pain during pregnancy.

Common questions about dysfunctional uterine bleeding

Is dysfunctional uterine bleeding serious?

Usually not, but it shouldn’t be ignored. Most abnormal bleeding comes from hormone changes, fibroids or polyps, and all of these can be treated. Heavy bleeding over months can cause anemia. In women over 45, a change in bleeding sometimes points to precancer of the uterine lining, so a checkup matters.

Why is my period late if I’m not pregnant?

Stress, illness, weight loss or gain, hard exercise and travel can all delay ovulation, so the period comes late. Common medical causes include PCOS, thyroid problems, breastfeeding and the years before menopause. If you’ve had sex, take a pregnancy test first. See a doctor if you miss three periods in a row.

Why am I bleeding again after my period ended?

Light spotting between periods can come from ovulation, a new birth control method or a missed pill. Doctors call bleeding on birth control breakthrough bleeding. Polyps, fibroids, infection and irritation of the cervix can also cause it. If bleeding between periods keeps happening, follows sex or is heavy, see a doctor.

Is a short or light period normal?

Often, yes. A period of 2 or 3 days, or a lighter flow than usual, can be normal, especially with hormone birth control, stress, weight changes or getting older. Light bleeding can also happen in early pregnancy, so take a test if you could be pregnant. Tell your doctor about changes that last.

Can I get pregnant if my bleeding is irregular?

Often, yes, but it may take longer. Bleeding from skipped ovulation means eggs are released less often, which makes timing harder. Treating the cause, such as PCOS or a thyroid problem, often helps. If you are trying to get pregnant, tell your doctor so your treatment fits your plans.

Questions to ask your doctor

• What do you think is causing my bleeding?
• Do I have anemia, and do I need iron?
• Which treatment fits my plans for pregnancy?
• How long should I try a treatment before we change it?
• Do I need a biopsy?

Learn more

• Abnormal uterine bleeding (MedlinePlus, U.S. National Library of Medicine)

This guide is general information and doesn’t replace advice from your own doctor. Last updated October 2026.