Passing Big Blood Clot on Period

Medical illustration showing menstrual cycle phases with highlighted blood clot formation

Passing large blood clots during menstruation typically means you're losing more than 80ml of blood-more than a normal period. These clots form when blood loss is heavy enough to prevent anti-clotting agents in vaginal blood from working effectively.

How Menstrual Clots Form

During a heavy flow, blood cells don't have time to properly mix with anticoagulant proteins. The result is semi-solid clumps of blood cells and tissue. Most menstrual clots measure less than an inch; anything larger may indicate an underlying issue.

Main Causes

The most common cause is simply having a heavy period. Other triggers include:

Hormonal imbalances: Conditions like fibroids or endometriosis disrupt normal uterine shedding.
Pregnancy complications: Miscarriages or ectopic pregnancies often cause abnormal bleeding.
Blood disorders: Conditions like von Willebrand disease affect clotting factors.

When to See a Doctor

Consult a healthcare provider if you experience any of these symptoms alongside clots larger than a quarter:

Bleeding that soaks through a pad or tampon every hour for multiple hours
Severe cramping or lower abdominal pain
Fever or signs of infection
Dizziness, fatigue, or signs of anemia

According to the American College of Obstetricians and Gynecologists, prolonged heavy bleeding (7+ days) warrants medical evaluation.

Common Misconceptions

What to Expect at Your Appointment

Your doctor will likely ask about your medical history and perform a pelvic exam. Tests may include:

Ultrasound to check for fibroids or cysts
Blood tests to assess hormone levels or anemia
Endometrial biopsy to examine uterine tissue

Treatment options range from hormonal birth control to surgical interventions for underlying conditions.