Changes to period duration and heaviness can happen for various reasons. Conditions affecting the ovaries, womb, or hormone levels can cause sudden heavy periods. These include uterine polyps, endometriosis, and more.

According to the Centers for Disease Control and Prevention (CDC), heavy periods are among the most common health issues that females report to doctors.

In this article, we look at what a normal period is, the causes of a sudden heavy period, how to manage it, and when to see a doctor.

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Several conditions may cause a sudden heavy period.

Normal menstrual bleeding lasts less than 1 week. However, the amount of bleeding can vary from person to person and from one period to the next.

According to the CDC, heavy menstrual bleeding, or menorrhagia, occurs when someone:

  • bleeds for more than 7 days
  • has to change their pad or tampon after less than 2 hours
  • passes clots that are roughly the size of quarters
  • has to use more than one sanitary product at a time

A person with heavy periods may also experience intense cramping, back pain, or symptoms of anemia, such as fatigue and weakness. They may not be able to participate in their usual activities.

If a person experiences these symptoms, it could be a sign of an underlying condition, especially if they continue for several months.

Several conditions and factors can cause a heavy period to occur. These include:

Uterine polyps or fibroids

Uterine polyps are small, noncancerous growths that occur on the uterus. According to an article in SAGE Open Medicine, uterine polyps often have no symptoms. However, they can cause health issues, such as heavy bleeding and infertility.

In some cases, uterine polyps become cancerous, so it is important to see a doctor. Treatment for uterine polyps may involve:

  • watchful waiting to assess whether they pose a risk of becoming malignant
  • hormone therapy
  • surgical options, such as a hysteroscopic polypectomy (removal of the polyp)

Fibroids are noncancerous growths in or around the uterine lining. According to the Office on Women’s Health (OWH), people may not always experience symptoms. In those who do, the symptoms can be hard to live with and may include:

  • heavy bleeding
  • pain during sex
  • lower back pain
  • issues with fertility
  • complications during pregnancy
  • a feeling of fullness in the abdomen
  • frequent urination

Treatment options typically include medications, such as birth control, or surgery to remove the fibroids.

Pregnancy complications

According to the CDC, complications relating to pregnancy, such as a pregnancy loss or ectopic pregnancy, can cause abnormally heavy bleeding.

A pregnancy loss, or miscarriage, occurs when a fetus dies in the uterus. The body will shed the lining of the uterus and the fetus, which can result in heavy vaginal bleeding.

An ectopic pregnancy occurs when a fertilized egg develops outside of the uterus, often in the fallopian tube. As the pregnancy progresses, the fetus can rupture the fallopian tube, causing life threatening internal bleeding.

An ectopic pregnancy can result in symptoms such as:

  • lower back pain
  • vaginal bleeding
  • mild cramping on one side of the pelvis
  • mild pain in the abdomen or pelvic region

If an ectopic pregnancy occurs, a doctor will terminate the pregnancy because it cannot safely come to term.


Endometriosis occurs when tissue from the womb lining grows outside of the womb, causing severe pain and, sometimes, heavy bleeding during a period. It is a long-term condition that may affect more than 11% of females between the ages of 15 and 44 in the United States.

The symptoms of endometriosis include:

  • very painful menstrual cramps
  • chronic lower back and pelvic pain
  • pain during or after sex
  • painful bowel movements or urination during a period
  • bleeding or spotting between periods
  • digestive symptoms
  • infertility

There is no cure for endometriosis, but people can manage the condition by reducing estrogen levels. Estrogen helps the womb lining thicken before a period, so lowering the levels of this hormone may improve symptoms. People can do this naturally by maintaining a moderate weight, avoiding alcohol and caffeine, and getting regular exercise.

Some people may also find that forms of birth control with low doses of estrogen also lessen the symptoms of endometriosis.

Bleeding disorders

Bleeding disorders may make periods heavier than usual. According to the OWH, about 1 in 10 women with heavy periods have a bleeding disorder. Of these, the most common are hemophilia and Von Willebrand’s disease (VWD).

Common symptoms of bleeding disorders include:

  • anemia
  • heavy vaginal bleeding from menstruation
  • heavy vaginal bleeding from conditions unrelated to menstruation
  • easy bruising
  • prolonged bleeding following injuries or surgery
  • nosebleeds that are difficult to control
  • bleeding in muscles, joints, or organs

Some common treatments for bleeding disorders include:

  • hormonal medications
  • clotting factor concentrates
  • antifibrinolytics, which prevent blood clots from breaking down too quickly
  • iron supplements

Uterine cancer

According to the National Cancer Institute, there are two types of uterine cancer. Endometrial cancer is a more common type that is treatable and curable. Uterine sarcoma is a rare type of cancer in the uterus that is harder to treat and more aggressive.

Symptoms of uterine cancer include:

  • heavy vaginal bleeding not related to the menstrual cycle (e.g., after menopause)
  • pain during sex
  • pain in the pelvic area
  • trouble urinating or painful urination

Treatments for endometrial cancer can include radiation therapy, chemotherapy, surgery, and hormone therapy.

Other disorders

High estrogen levels can cause heavy periods. A person may have high estrogen for a variety of reasons. Obesity is one possible cause of high estrogen levels in some females.

Medications that thin the blood can also cause heavy bleeding, as can some types of birth control. A person may experience a sudden heavy period as a result of using an intrauterine device (IUD), for example.

According to the CDC, a person living with certain long-term illnesses may also experience heavy menstrual bleeding. These illnesses include:

If a heavy period is due to an underlying condition, treating the condition will improve this symptom. In the meantime, a person can cope with heavy menstrual bleeding through self-care.

A person can take steps such as:

  • using two period products or wearing two layers of underwear
  • changing pads or tampons more frequently, including in the middle of the night if necessary
  • using a heat wrap, heating pad, or warm bath to ease cramps
  • taking over-the-counter pain relievers, such as ibuprofen
  • getting regular exercise
  • wearing dark clothing to reduce visible stains from leaks

If the heavy bleeding occurs as a side effect of a type of birth control, a person may wish to try another birth control method.

A person should talk to their doctor if they notice that their periods are noticeably heavier than usual, especially if they interfere with daily activities. They should also see a doctor if:

  • their period lasts longer than 8 days
  • they bleed through one or more pads every 2 hours
  • they feel dizzy, lightheaded, tired, or have trouble breathing
  • they pass large clots

While heavy bleeding and severe cramps are a common health problem, they are not normal. It is important to mention pain or other accompanying symptoms to a doctor.

A sudden heavy period may be the result of normal hormonal fluctuations or a side effect of birth control. However, heavy periods can also indicate an underlying health condition.

A person should talk to their doctor if they experience heavy bleeding or cramping that prevents them from completing normal activities.

If a heavy period occurs, a person can take steps at home to manage it, such as wearing darker clothing, using heat therapy, and using more than one sanitary product.