Period Blood Clots

If you’ve ever noticed any blood clots during menstruation, you may wonder what is going on. Period blood clots are gel-like lumps of coagulated blood and tissue expelled from the uterus, usually alongside thinner period blood. These clots can be bright or dark red; they often vary in size and consistency. Menstrual blood clots tend to form toward the beginning of your period or on heavy days when menstrual blood flows faster than your body’s natural anticoagulants can thin it.

In most cases, passing small, occasional menstrual blood clots (no larger than a quarter) is considered normal and nothing to worry about. However, passing large clots –– especially when accompanied by other symptoms like heavy bleeding, severe cramps, and low energy levels –– can signal that something is wrong. 

One common underlying health condition that may explain your period blood clots is the presence of uterine fibroids. Fibroids are non-cancerous growths that develop in or on your uterus. An estimated 70 to 80 percent of women develop fibroids by age 50. 

Uterine fibroids vary in type, size, and number, and can cause a range of painful, uncomfortable, and inconvenient symptoms such as:

  • Heavy and prolonged menstruation between or during your periods
  • Anemia, which can lead to fatigue
  • Pain during intercourse
  • Frequent urination
  • Constipation and/or bloating
  • Pain in your pelvis or lower back
  • Increased menstrual cramping
  • Stomach swelling
  • Menstrual blood clots that are larger than a quarter  

Here’s everything you need to know about period blood clots, health conditions that can cause them, and how to find relief from painful and unpleasant symptoms. 

What Causes Blood Clots During Periods?

Although your small period blood clots may be normal, there are several health conditions that can be responsible for large blood clots in period blood. To determine what is causing your clots, we recommend tracking any and all symptoms related to your menstrual cycle and discussing these with your doctor. 

Health conditions that can cause blood clots during periods include:


  • Hormonal imbalance: If you have a hormonal condition such as hypothyroidism or Polycystic Ovary Syndrome (PCOS), or are going through menopause or perimenopause, this may explain your period blood clots
  • Pregnancy: Although not always the case, vaginal blood clots can indicate a miscarriage. If you are pregnant and notice blood clots of any size, please seek emergency medical care.
  • Endometriosis: This painful condition of the reproductive tract occurs when uterine tissue develops outside of the uterus. Symptoms include severe menstrual cramps, lower back and pelvic pain, digestive issues, abnormal bleeding, and infertility. 
  • Adenomyosis: Your menstrual blood clots may be caused by adenomyosis, which occurs when the inner lining of the uterus grows into and thickens the muscular walls of the uterus. Common symptoms include severe cramps, abdominal pressure, bloating, and heavy periods. 
  • Cancer: Uterine and cervical cancers can result in blood clots during menstruation. Other issues to be on the lookout for include abnormal period bleeding, pelvic and abdominal pain or pressure, fatigue, weight loss, and digestive problems. 
  • Uterine fibroids: These common, non-cancerous tumors develop in or on the uterus and can lead to painful, uncomfortable, and inconvenient symptoms. They can also damage surrounding organs and impact fertility. Women with fibroids often experience period blood clots, heavy menstrual bleeding, severe cramps, frequent urination, painful sex, and low energy levels. 


Because many of the above health conditions have overlapping symptoms, it is critical to visit your doctor to receive an accurate medical diagnosis. Fortunately, once the underlying cause is determined, a wide variety of treatments can help alleviate your pain, discomfort, and period blood clots. For many, treatment can improve overall quality of life. For some, appropriate treatment may even save lives.

When to Talk to a Doctor About Period Blood Clots

Although your menstrual blood clots may ultimately be considered normal, the only way to know for sure is to discuss them with a medical professional. In general, we recommend contacting your doctor for a full evaluation when:

  • You notice period blood clots that are larger than a quarter
  • You have any concerns about your period
  • You experience any changes in your menstrual cycle
  • Your blood clots are accompanied by other symptoms like heavy bleeding, severe cramps, frequent urination, bloating, digestive issues, low energy, and painful sex
  • You are pregnant and pass any size blood clot; this is considered a medical emergency

To make an accurate diagnosis, your doctor will discuss relevant symptoms with you, conduct a physical exam, and possibly order blood tests and medical imaging studies like ultrasound or MRI. 

Uterine fibroids can often be detected during a routine pelvic exam. If your doctor suspects you may have fibroids, they will perform or order an ultrasound to confirm the diagnosis and determine the location, size, and number of growths. If more information is required, they may also order an MRI. This detailed information can help inform the best treatment decision for you. 

Contact USA Fibroids Today!

If you’ve been diagnosed with uterine fibroids, we recommend visiting a fibroid specialist to explore your full range of treatment options. Fibroid treatment is usually recommended when symptoms are interfering with your career, social life, intimate relationships, self-esteem, or ability to perform daily activities. 

At USA Fibroid Centers, we aim to inform women about both surgical and non-surgical fibroid treatments. Many believe that a hysterectomy –– the complete surgical removal of the uterus –– is their only option, but this isn’t true. Our fibroid experts specialize in a minimally-invasive, outpatient procedure called Uterine Fibroid Embolization (UFE). UFE can eliminate your symptoms without surgery, preserve your uterus and fertility, and quickly get you back to living life to its fullest. 

Don’t let your periods control your life any longer! Schedule an appointment at one of our dozens of clinic locations or discover our convenient telemedicine options. Either way, we look forward to hearing from you soon.

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