What Does Big Blood Clots in Period Mean?

Medically Reviewed on 1/6/2022
heavy periods with blood clots
It is normal to pass blood clots occasionally during menstruation; however, frequently passing large blood clots could be a sign of any underlying issue.

When you pass blood clots during your periods occasionally, it is normal. Many women pass blood clots on the second or third day of their periods.

However, if the bleeding is very heavy during all days of the period, you may pass frequent clots, which may be a cause for concern.

Menorrhagia means menstrual bleeding that is more (heavier) than usual.

  • If you change your tampon every two hours or sooner
  • If you pass blood clots larger than the size of a quarter on any day of the period
  • If your periods last more than seven days
  • If your cycle is less than 21 days
  • If you need to change pads or tampons in the middle of the night

Many conditions may affect your menstrual cycle, making them heavier and prone to passing clots.

12 reasons why you may be passing big blood clots

  1. Stress
    • Any type of stress (physical or emotional) can cause the release of stress hormones in the body.
    • This can cause hormonal imbalance that may lead to heavier bleeding and clots.
  2. Thyroid disorders
    • If you suffer from an over-functioning (hyperthyroidism) or under-functioning (hypothyroidism) thyroid gland, it can affect the hormones that regulate your period. This may impact the flow and severity of your menstrual cycle.
      • The thyroid is a butterfly-shaped gland located in the front of your neck.
      • The thyroid imbalances may be caused by various conditions, including stress, autoimmune disorders, iodine or selenium-deficient diet, drugs, or tumors.
    • If your doctor suspects that you suffer from a thyroid condition, they will do a physical examination, run a thyroid panel to estimate TSH, T3, and T4 along with antithyroid antibody levels in your blood. This may or may not be followed by thyroid sonography.
  3. Uterine fibroids
    • Uterine fibroids grow inside the uterus and its lining can cause a heavier period than normal.
    • Similarly, small growths called the uterine polyps that grow along with the cervix, or the lining of the uterus can cause heavy bleeding and blood clots in your menstrual flow.
    • The uterine fibroids are often diagnosed using sonography, uterine computed tomography scan, and laparoscopic procedures.
  4. Birth control
    • Many types of birth control, especially intrauterine contraceptive devices (IUCD) inserted inside the uterus can cause you to experience heavier bleeding or clots during periods. This may happen up to a year after the IUCD was inserted.
  5. Medications
    • Many drugs can cause clots and heavier periods. Medications, such as blood thinners, anticoagulants (Warfarin, clopidogrel, aspirin), contribute to abnormal menstrual flow and bleeding. Sometimes, they may cause clots.
  6. A missed abortion
    • An undetected miscarriage early in the pregnancy can often be confused for a large clot.
    • The pregnancy test may or may not be positive before the period starts. It may be accompanied by abdominal cramps and general malaise (feeling of being unwell).
  7. Bleeding disorders
    • If you suffer from hematological disorders, such as von Willebrand disease, a certain type of blood cancer (leukemia), liver disorders, or thrombocytopenia, you may have heavier periods and pass clots.
  8. Endometriosis
    • Endometriosis is a condition in which the uterine tissue that normally grows inside of the uterus develops outside the uterine cavity. This can cause heavy clots during your cycle, abdominal pain, and severe cramps.
  9. Polycystic ovarian syndrome (PCOS)
    • Women who suffer from PCOS often have heavy clots and bleeding. This is a metabolic disorder where the woman has ovulation issues and irregular periods along with other abnormal parameters, such as increased fasting insulin, abnormal blood progesterone to estrogen ratio among others.
  10. Cancers
    • Uterine and cervical cancers are a rare cause of heavy periods and clots.
  11. Adenomyosis
    • The uterine tissue that normally lines the uterus (endometrial tissue) grows into the muscular wall of the uterus (myometrium).
  12. Miscellaneous
    • In many cases, no obvious cause is found despite investigations. In these cases, symptomatic treatment and lifestyle modifications are often prescribed.

How big should period clots be?

Ideally, there should be no clots when you are menstruating.

  • Small clots which are less than the size of a dime or quarter during their first or second day of the period are probably normal.
  • However, if you pass larger clots, such as golf ball-sized clots, along with abdominal pain strong enough to disrupt your daily routine, it is probably a warning sign that needs to be investigated.

How can I stop heavy periods with clots?

It is important to discuss with your doctor if you have heavy periods with clots. They will conduct a physical examination along with blood tests, sonography, and even laparoscopic procedure if required.

Home remedies, such as taking a day off during heavy days and taking it easy, help a lot of women. Other measures include:

  • using heating pads to help with abdominal cramps,
  • staying hydrated with water, green tea, and juices, and
  • avoiding alcohol and excess caffeine.

Ensure that you have a nutrient-rich meal with plenty of complex carbs.

  • Herbal remedies, such as ginger capsules, soaked fenugreek seeds, myrtle fruit syrup, and pomegranate flower capsules have no U.S. Food and Drug Administration approval but may be tried in some cases.
    • These are known to reduce cramping and bleeding.
  • Stress management techniques, such as yoga and meditation, may help.

If these remedies do not help, you may be placed on medication.


In severe cases, surgical interventions may be required, such as the following:

  • Hysteroscopy: This is a laparoscopic (minimally invasive) procedure that visualizes and removes polyps and uterine fibroids to help reduce a heavy flow.
  • Dilation and curettage: This is often done in cases of adenomyosis and involves removing the uterine lining to limit the bleeding. You may need to undergo the procedure more than once.
  • Endometrial ablation or resection: These procedures involve using techniques to destroy most or all the inner uterine lining.
  • Hysterectomy: This is an extreme measure that involves complete removal of the uterus.


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Medically Reviewed on 1/6/2022
Image Source: iStock Images

Centers for Disease Control and Prevention. Bleeding Disorders in Women. https://www.cdc.gov/ncbddd/blooddisorders/women/menorrhagia.html