Why Is My Period Lasting So Long? 7 Causes & What to Do

Updated in December 2022

A period that lasts for over 8 days may be a sign of an abnormality in the reproductive system, like fibroids, polyps or IUD use. Periods normally last for 4 to 7 days, with flow being heavier in the first days and progressively reducing, however this may differ in women with menopause, hemophilia or endometrial cancer. 

Significant blood losses with a heavy period can cause symptoms like weakness, dizziness, pallor or anemia. It is important to monitor how many pads or tampons you soak through and how quickly, so that blood losses can be tracked. 

Prolonged periods with a coffee ground appearance can be a sign of an STI, endometriosis, or even pregnancy. You are advised to report this finding to a gynecologist to start treatment as necessary.

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What causes a long, heavy period?

The main causes of prolonged menstruation with a heavy flow are: 

1. Uterine fibroids

Uterine fibroids are benign tumors that develop on the muscular layer of the uterus. The symptoms they cause depend on their size, quantity and where they are located within the uterus. Common symptoms include abdominal cramping, breakthrough bleeding, heavy and long periods, constipation, and pain during sex. 

What to do: It is important to consult a gynecologist if you present with the above symptoms. Treatment will depend on the quantity, size and presenting symptoms. The doctor may recommend anti-inflammatories, hormonal therapy and surgery. 

2. Menopause

Some hormonal changes, like menopause, can lead to irregular periods. Hormones can influence how frequent menstruation occurs, and how heavy flow is. 

What to do: Possible symptoms of menopause should be assessed by a gynecologist, who may opt to order blood work to confirm hormonal levels. Treatment may involve hormone replacement therapy. 

3. Uterine polyps

Uterine polyps are small lumps that appear on the internal uterine wall. They can occur with menopause or other hormonal changes, and can lead to breakthrough bleeding, infertility, and abdominal pain during menstruation. 

What to do: In most cases. polyps do not require any treatment and the gynecologist may just monitor them. Treatment is indicated for women who present with a greater risk of developing uterine cancer. 

4. Hemophilia

Hemophilia is a genetic disease characterized by the lack of or decreased amount of blood clotting factors that are necessary for coagulation. This disease is associated with bleeding gums, nose bleeds, blood in the urine or stool, bruises throughout the body, and heavy or long periods. 

What to do: Although there is no cure for this disorder, treatment can help to prevent recurrent bleeding. Treatment may involve clotting factor replacement to ensure levels are within limits. Concentrated clotting factors are administered during active episodes of bleeding. 

5. Copper IUDs

Copper IUD is a non-hormonal contraceptive, made with plastic lined with copper. The copper is continuously released in the uterus, which causes changes to the uterus and cervical mucus, resulting in sperm death. Using a copper IUD can cause secondary effects like anemia as well as long, heavy periods. 

What to do: Very heavy periods that occur after copper IUD placement should be reported to the gynecologist, who may consider alternative contraceptive methods. Learn more about the birth control options available. 

6. Endometrial cancer

Endometrial cancer is characterized by the presence of malignant cells along the uterine wall. It can cause symptoms like heavy bleeding between periods or after menopause, pelvic pain and weight loss. Read more about the symptoms of cancer that you should not ignore. 

What to do: If you suspect cancer, you should see a doctor immediately for thorough cancer testing and diagnosis. A prompt diagnosis can guide treatment, which may involve chemotherapy, radiation therapy or hormone replacement therapy. Very severe cases may require surgery for the removal of the uterus and any other affected tissue. 

7. Medication use

Using anticoagulants (like heparin), or antiplatelet drugs (like acetylsalicylic acid or clopidogrel) can cause very heavy or longer periods than normal. It may even lead to anemia if left untreated. 

What to do: You should report this symptom to your prescriber to assess the possibility of swapping the medication or adjusting the dose. 

When long periods are normal

It is normal for periods to become irregular or last for longer after taking the morning-after pill. Adolescents who have not achieved a regular cycle yet and women entering menopause may also experience long periods, as hormone levels tend to fluctuate.