Updated: 2021, Jun 16

Causes of Blood Clots and Other Menstrual Problems

Learn what causes vaginal blood clots and how it can affect the other menstrual problems.

Vaginal blood clots occur during the menstrual cycle. In most cases, it is perfectly normal for a woman’s monthly flow to become thicker or change in color.

Causes of Blood Clots and Other Menstrual Problems

On rare occasions, these clots can be a sign of more serious problems. During menstruation, the lining on the uterus will thicken in preparation of receiving a fertilized egg.

When a pregnancy does not occur, the body naturally begins to expel the excess lining and blood. This is when vaginal blood clots can occasionally happen.

Vaginal Blood Clots

During her monthly period, a woman’s body naturally produces anticoagulants. These are released to help prevent the menstrual blood from developing clots.

Towards the end of her cycle, the body may work harder at dispelling the last of the excess uterine lining and blood.

This increased blood flow can occasionally be dispelled from the vagina before the anticoagulants can be effective, resulting in the appearance of blood clots.

While most of these clots are small and harmless, clots larger than a quarter or accompanied by pain should speak with a healthcare professional.

Women who regularly experience heavier menstrual cycle flows towards the end of the periods might also be at an increased risk of developing anemia.

Fatigue and muscle weakness can also be symptoms of an abnormally heavy blood flow that normally includes blood clots.

Causes of Blood Clots and Other Menstrual Problems

While it is normal for women to experience heavier flows and occasional clotting, there are several conditions that can cause problematic vaginal clots to form.


*All individuals are unique. Your results can and will vary.

Women who are pregnant, or who suspect that they might be pregnant can experience vaginal clotting. Unfortunately, this is often a sign of a miscarriage and a healthcare professional should be consulted.

Another medical problem that can cause vaginal blood clots is fibroids. Specifically uterine fibroids. These form on the uterus and are non-cancerous, but they can be responsible for causing vaginal blood clots to form during menses.

Uterine fibroids do not always cause clotting to occur, and recent studies are beginning to suggest that many women do not develop any symptoms associated with this problem.

Hormonal Changes and Vaginal Blood Clots

Hormonal Changes and Vaginal Blood Clots

One of the most common causes for the appearance of blood clots occurs when there is a change in the hormonal levels in the body.

In a woman’s body, the hormones progesterone and estrogen help to regulate her menstrual cycle. This also entails creating and removing the lining of the uterus.

When the hormonal levels are drastically changed, it can cause the lining of the uterus to continue to thicken.

As the body begins to dispel the lining and accompanying blood and fluid, the excess tissue can cause blood clots to form.

There are several different causes that can change the hormone levels in the body including,

  • Experiencing menopause.
  • Sudden or rapid changes in weight gain or loss.
  • Certain medications can cause hormonal imbalances in the body, but these levels will usually return to normal.
  • Obstruction in the cervix, uterus, or vaginal canal. Anything that can either slow down or block the flow of menses from the body.
  • A large or stretched uterus. This normally occurs after childbirth and will return to normal size on its own. Otherwise, the enlarged uterus can either changed the direction of the blood flow or slow it down, resulting in the appearance of blood clots.

Two conditions known as endometriosis and adenomyosis can also cause blood clots to form in the menstrual flow.

Endometriosis occurs when the tissue that normally helps to line the uterus begins to grow outside. Adenomyosis is similar, except the tissue can be found growing in the uterine walls.


If you are experiencing heavier than normal periods and vaginal blood clots, there are a few different tests that can help to determine the cause of the problem.


*All individuals are unique. Your results can and will vary.

These can include ultrasounds and MRI. Both of these procedures are noninvasive and will record images of the female reproductive system.

Other methods for diagnosing the cause of the vaginal blood clots can also include,

  • Normal blood work.
  • A dilatation and curettage. This is when a small piece of tissue is removed from the uterus, with the help of a small instrument. The procedure is simple and only a small amount of discomfort is normally felt.
  • In some cases, a biopsy will need to be performed. A small piece of tissue will be cut off and sent for further analysis. This is usually only done when there is a risk of certain cancers developing.


Michael Wight

Michael Wight is a health enthusiast and blogger. He contributes to different websites in the health and fitness niche.

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