Menstrual Clots: Normalcy, Causes and Treatment Demystified

It is normal to pass small sized clots during your periods. However, passage of clots bigger in size on a regular basis is a sign of some underlying health condition. Many of the menstruating women will experience menstrual clots at some time or other. These clots look like gel made of coagulated tissue and blood, which has being expelled from the uterus during periods. These clots look like small clumps of jam or stewed strawberries and can be of bright to dark red in color.

If the menstrual clots are small in size, lesser than a quarter and pass only occasionally, then it is normal and nothing to worry about, as menstrual clots by themselves are not harmful. Having large sized menstrual clots on a regular basis on your period can indicate medical condition and needs medical attention. Normal menstrual clots are bright to dark red in color, look like tiny pieces of stewed fruit. Normal menstrual clots are smaller than a quarter and occur occasionally, mostly towards the start of the cycle. Clots that are not normal are bigger than a quarter and occur more frequently and persistently.

Women of childbearing age with menstrual cycle will shed their lining of the uterus (endometrium) every 28 to 35 days. This uterine lining or endometrium thickens and grows over the month in response to estrogen and the purpose of this is to make a home for the fertilized egg to get embedded and grow in the endometrium. If the woman doesn’t get pregnant, then the hormones trigger the shedding of the lining in the form of blood and small clots every month, which is known as menstruation or a menstrual period or simply a period.

When the endometrium is expelled from the uterus, it is mixed with: blood, mucus, blood byproducts and tissue. This mixture makes up the uterine lining and is expelled from the uterus via the cervix and out of the vagina.

As there is shedding of the uterine lining, it collects at the base of the uterus, waiting for the contraction of the cervix to expel its contents. To help with the breakdown of this coagulated and thickened tissue and blood, the body produces anticoagulants to thin down this material so it can pass freely from uterus, via cervix and outside the vagina. However, when the flow of blood is more than the production of anticoagulants, then it causes the formation of menstrual clots.

This formation of menstrual blood clot commonly occurs when the blood flow is heavy. For women with normal flows, they tend to have heavy flow days in the start of their period and this is often short-lived. The flow is thought to be normal if the bleeding lasts for about 4 to 5 days with 2 to 3 tablespoons of blood or less ⁽¹⁾.

For women experiencing excessive bleeding with heavier flows and clot formation, the menstrual cycle can be prolonged. About one-third of menstruating females have heavy flows such that they soak through a tampon or pad every hour for many hours.

Hormonal and other physical factors affect the menstrual cycle and create a heavy flow. Having heavy menstrual flows or cycle increases the chances of having menstrual clots too. Some of the health conditions which cause menstrual clots are:

Endometriosis: This is a condition where the cells which are similar to uterus lining, (endometrial cells) start to grow into the reproductive tract and outside the uterus ⁽²⁾. When the time comes for the period to occur, these cells can produce: nausea, vomiting, and diarrhea at the time of the period; cramps with painful periods; painful intercourse; pelvic pain; infertility and abnormal bleeding, which can be accompanied with clotting. The exact cause why endometriosis occurs is not known; however, hormones, heredity and pelvic surgery in the past are thought to play a role in causing this condition.

Uterine Obstructions: Any type of conditions that engorge or increase the size of the uterus can cause extra pressure on the wall of the uterus. This causes increased menstrual flow and clots. Uterine obstructions disrupt the uterus’s ability to contract and when it does not contract in the proper manner then there is accumulation and coagulation of blood within the uterine cavity resulting in clot formation, which is later expelled when the woman has had her period.

The cause of uterine obstructions can be: endometriosis, fibroids, malignant tumors, fibroids and Adenomyosis. Fibroids are usually non malignant, muscular tumors that develop in the uterine wall and other than increasing the menstrual bleeding, they are also responsible for producing clots: low back pain; irregular menstrual cycle; painful intercourse; problems with fertility and a protruding belly.

According to studies, around 80% of women will develop fibroids by the time they reach the age of 50 ⁽³⁾. It is not clear why this happens; however, genetics and hormones like progesterone and estrogen are thought to play a role in the development of fibroids.

Adenomyosis: This is a condition, when for unknown reasons, the uterine lining starts growing into the wall of the uterus resulting in thickening and enlargement of uterus ⁽⁴⁾. This causes heavy and prolonged bleeding, which causes the uterus to grow more than double its normal size ⁽⁵⁾.

Hormonal Imbalance: There needs to be a balance of hormones, such as progesterone and estrogen for the uterine lining to develop and get thick properly for the fertilized egg. If there is an imbalance of the hormones, then it can cause heavy bleeding. Some of the causes of hormonal imbalance include: menopause, perimenopause, stress and significant weight loss/gain. Irregular menstruation is the primary symptom of hormonal imbalance, which can cause delayed or heavy periods or can cause the patient to miss the period completely.

Miscarriage: According to experts, about half of the entire pregnancies can result in miscarriage (6). Most of these miscarriages occur even before the patient knows she is pregnant. When there is loss of pregnancy in its earlier stages, it can cause cramping, heavy bleeding and clotting.

Von Willebrand disease: This is a rare disease which can also cause heavy menstrual flow and can occur in about 5 to 24% of female having chronic heavy bleeding. Von Willebrand disease can be the cause of the heavy bleeding, if it happens on a regular basis and the patient starts to bleed easily after getting a minor injury or cut and also if there is easy bleeding from the gums, then it can be an indication of having this disease.

Cancer: Rarely cancerous tumors of the cervix and uterus can cause heavy menstrual bleeding.

Iron deficiency anemia is one of the major complications of having heavy menstrual bleeding. Anemia occurs when there is insufficient iron in the blood and healthy red blood cells are not produced. Some of the common symptoms of anemia are: weakness, pallor, fatigue, breathlessness and chest pain.

The doctor will conduct a thorough medical and physical exam and ask about things, which can cause heavy bleeding, such as using birth control, past pelvic surgeries or if the patient has been pregnant previously. The doctor can also examine the uterus. Other than this, blood tests are done to check for hormonal imbalances. Imaging tests, such as an ultrasound or MRI can also be done to look for endometriosis, fibroids and other obstructions in the uterus.

To control menstrual clots, controlling heavy menstrual bleeding is the best method to treat this.

Treatment with Medications: Hormonal contraceptives help in stopping the growth of the lining of the uterus. Intrauterine device (IUD) which releases progestin can help with decreasing the menstrual flow by about 90% ⁽⁷⁾. Birth control pills also can help in reducing the heavy menstrual flow by about 50% ⁽⁸⁾. 

Hormonal contraceptives also help in slowing the development of fibroids and other adhesions in the uterus. For women who do not or cannot use hormones, a good alternative is the medication tranexamic acid, which influences blood clotting.

Treatment with Surgery: In some patients, surgery is needed for treating the cause of heavy bleeding and clots. If fibroids are the cause for heavy bleeding and clots and if medications are not working then surgery is done to remove them. The type of surgery done depends on the location and size of the fibroid or other uterine growths. If the fibroids are large in size then the patient may need a myomectomy where large incision is made on the abdomen to get to the uterus. If the growth is small, then laparoscopic surgery can be done. There are some patients who can choose to undergo hysterectomy where the uterus is removed.

Treatment with Dilation and Curettage: After a miscarriage, the dilation and curettage procedure done can also help in finding the underlying cause for heavy bleeding or it can act as a treatment for other conditions. This procedure involves widening the cervix and then with the help of the instrument, scraping the lining of the uterus. This is commonly done in an outpatient setting with the patient under sedation. This procedure is not a cure for heavy bleeding; however, it gives some relief for some months till the uterine lining gets thick again.

Patient needs to talk with their doctor about the pros and cons of the different treatments and decide what is best for them.

Having heavy menstrual periods drastically affects the patient’s life. Other than the physical symptoms, such as fatigue and cramping, it also makes it difficult for the patient to pursue normal physical activities, such as playing any sports or swimming or even relaxing and sleeping.

• Taking OTC pain killers, such as ibuprofen when the period starts and taking it through the days when the bleeding is at its heaviest flow helps in alleviating cramping and in also reducing the blood flow ⁽⁹⁾.
• Always wear a pad or tampon on the days of heaviest flow. Two pads together can also be used.
• Wearing dark-colored clothes helps in hiding kind of accidents or leaks.
• It is better to place a waterproof sheet over the bedspreads when sleeping at night.
• It is advisable to carry period supplies wherever you go. Always keep a separate stash in your car, purse, vanity, dresser or office desk drawer.
• Keep knowledge of where the public bathrooms are located in case of emergency.
• Always follow a healthy diet and drink lot of water. Heavy bleeding takes a lot of toll on the physical health of the patient. So it is important to eat healthy food, especially iron rich foods to combat the blood loss due to heavy flow.

Note: Patients suffering from von Willebrand disease should stay away from NSAIDs.

Having small menstrual clots is normal in the reproductive life of menstruating women. Only if the clots are big in size accompanied by heavy prolonged flow, many times, then it becomes concerning. There are many treatments for menstrual clots accompanied by heavy bleeding, which the doctor will decide depending on the underlying cause and the duration and type of flow.

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