Blood Clots During Period: Are They Normal, What Are the Causes and Treatment



Are Period Clots Normal?

Passing blood clots during menstruation can be a pretty regular occurrence, and many women do experience it during their period. However, the length, amount, and frequency of menstrual bleeding vary from woman to woman and from period to period for every woman.

Bleeding heavily and passing period clots often can be a sign that something is wrong. Normal blood clots are smaller than a quarter, bright or dark red, and they only occur occasionally, usually around the beginning of the menstrual cycle. Abnormal menstrual blood clots are larger than a quarter in size and occur more frequently, usually due to heavy menstrual bleeding.

What Are the Most Common Causes for Menstrual Blood Clots?

There are several underlying conditions that can be causes of abnormal blood clots during the period. Some of the most common causes include:

Hormonal imbalance

The uterine lining relies on a balance of estrogen and progesterone to thicken properly, and heavy menstrual bleeding can be caused by an imbalance of these two hormones.

Some of the most common causes of a hormonal imbalance can include:

  • menopause
  • perimenopause
  • extreme or prolonged stress
  • significant weight gain or significant weight loss


Fibroids are generally noncancerous tumors that grow in the uterine wall. Besides heavy menstrual bleeding and large menstrual blood clots, fibroids can also cause:

  • low back pain
  • irregular menstrual bleeding
  • pain during penetration
  • fertility issues

Uterine Obstructions

Conditions that enlarge the uterus can put extra pressure on the uterine wall, increase menstrual bleeding, and create menstrual blood clots.

Some of the most common causes for uterine obstructions include:

  • fibroids
  • endometriosis
  • adenomyosis
  • cancerous tumors

Von Willebrand Disease

Von Willebrand disease (VWD) can be a cause behind a heavy menstrual flow that features large menstrual clots. VWD is a rather rare disease, and only 5 and 24 percent of women that deal with heavy menstrual bleeding and large menstrual clots are affected by it.

VWD can also cause you to bleed easily after a minor cut, and it can also cause your gums to bleed too easily.

If these symptoms fit you and if you suspect that VWD is the cause of your heavy bleeding, make sure to talk to your health care provider, as they will be able to help get you a diagnosis and treatment. 


Endometriosis is a condition in which endometrial cells grow outside the uterus and into the reproductive tract.

The most common symptoms of endometriosis include:

  • pelvic pain
  • nausea, vomiting, and diarrhea
  • discomfort during penetration
  • painful periods
  • infertility
  • abnormal bleeding that features large blood clots


A large percentage of pregnancies end in miscarriage, and for many of these pregnancies, a woman does not even know she is pregnant when the miscarriage happens. When a miscarriage happens in the early stages of pregnancy, it can lead to cramping, heavy bleeding, and clotting.

What Is the Treatment for Period Blood Clots?

Staying on top of heavy menstrual bleeding is the best way to deal with and treat menstrual clots. Some of the options include:

– Hormonal Contraceptives

Hormonal contraceptives and oral contraceptives, such as progestin-releasing intrauterine devices (such as hormonal IUD) and birth control pills, can reduce the usual flow. IUDs and birth control pills can therefore reduce menstrual blood flow and prevent blood clotting.

– Medication

For women who cannot or simply do not want to use hormonal therapy, a common option is a medication tranexamic acid (such as Cyklokapron and Lysteda), which stops heavy bleeding, lessens the blood flow, and prevents blood clotting.

However, the treatment should be prescribed and supervised by your doctor.

– Surgery

In rare cases, surgery might be needed. For women with uterine growths that don’t respond well to medication, such as fibroids, removal surgery might be necessary.

The type of surgery will depend on the size and location of the growth, and the options include myomectomy, laparoscopic surgery, and hysterectomy.

When To See a Healthcare Provider for Period Blood Clots During Your Period?

You should seek immediate medical attention from your healthcare provider if you experience heavy menstrual bleeding or if you experience menstrual blood clots that are larger than a quarter. If you have to change your pad or tampon every two hours or less for more than seven days, you are experiencing heavy menstrual bleeding.

In case that you think you could be pregnant or know that you are pregnant and experience large blood clots and heavy bleeding, seek immediate medical attention from your healthcare provider, as this could be a sign of miscarriage.

Related Questions:

When should I be concerned about period blood clots?

If you pass large blood clots (larger than the size of a quarter) and you need to change the tampon or pad after less than two hours, you are experiencing heavy bleeding, a condition that requires medical attention. If left untreated, heavy or prolonged bleeding will stop you from living a normal life, as well as cause anemia in the long run.  

Are period blood clots normal during the period?

For many women, passing large blood clots during their menstrual cycle is often a regular occurrence, especially the heaviest days of their period, which is different for every woman. However, if heavy bleeding and passing large clots happen more often than that, it is a cause for concern.

Can anemia cause large blood clots and heavy menstrual bleeding during the period?

Women who suffer from large clots and heavy menstrual periods are more prone to anemia where red blood cells are lost to bleeding.

How do blood clots look?

Menstrual clots are balls of coagulated tissue and menstrual blood that are expelled from the uterus during the period. Menstrual blood clots resemble clumps of fruit found in jam, and they can vary in color from bright to dark red.

What foods break down blood clots?

There are certain kinds of foods and other substances that can act as natural blood thinners and help reduce the risk of clots. Some of the most popular and widely-used ones include turmeric, cayenne peppers, ginger, garlic, vitamin E, ginkgo Biloba, grape seed extract, cassia cinnamon, and many others.

Can PCOS cause large blood clots?

PCOS is known as one of the most common causes of heavy periods, and they come with large blood clots in some instances.

Can an ovarian cyst cause blood clots during the period?

Large ovarian cysts can cause large period blood clots in certain cases.