Are period blood clots normal? What to know and when to seek help?

Seeing blood clots during your period can be alarming, but in most cases, it’s completely normal. These jelly-like clumps are a natural part of menstruation, especially during heavier flow days.

In this post, we’ll explain what period blood clots are, why they happen, and when they might signal something more serious. Plus, we’ll share medically reviewed insights and statistics to help you better understand your cycle.

What are period blood clots?

Menstrual clots are thick, gel-like blobs made up of blood, uterine tissue, and mucus. They can vary in color from bright red to dark maroon and often appear during the heaviest days of your cycle. These clots form when the body’s natural anticoagulants - which help thin menstrual blood - can’t keep up with the volume of bleeding¹.

Common characteristics of normal period clots:

Smaller than a quarter in size;
Occur occasionally, usually during the first few days of menstruation;
Bright or dark red in color;
Appear alongside heavier menstrual flow.

Most people will experience small clots during menstruation at some point, especially when flow is fast or heavy¹.

What causes period blood clots?

Your uterus sheds its lining (endometrium) each month in response to hormonal changes. As this tissue breaks down, it mixes with blood and exits through the cervix. To prevent excessive bleeding, your body releases coagulation proteinsthat help form clots².

Clots are more likely to form when:

Your flow is heavy and fast;
You’ve been lying down or sitting for a long time;
Blood pools in the uterus before being expelled.

This is why you might notice clots after waking up or standing suddenly².

When are period clots a cause for concern?

While most period blood clots are harmless, some may indicate an underlying condition. You should consult a healthcare provider if:

Clots are larger than a quarter;
You pass clots frequently throughout your cycle;
You experience heavy menstrual bleeding;
You have intense cramping or pelvic pain;
You notice changes in your cycle’s length, intensity, or regularity³.

Possible medical causes of abnormal clots:

Hormonal imbalances (e.g., estrogen dominance);
Uterine fibroids or polyps;
Endometriosis;
Adenomyosis;
Polycystic ovary syndrome (PCOS);
Thyroid disorders;
Bleeding disorders (e.g., Von Willebrand disease);
Miscarriage or ectopic pregnancy (if pregnant or suspect pregnancy)³⁴.

How common are period blood clots?

Up to 50–60% of menstruating people report passing clots during their period at some point in their lives¹;
Clots are most common during the first two days of menstruation, when flow is heaviest²;
Menorrhagia (heavy menstrual bleeding) affects approximately 1 in 5 people of reproductive age³.

How to support your menstrual health?

Here are some menstrual wellness tips to help manage clotting and heavy flow:

Track your cycle to notice patterns or changes;
Eat iron-rich foods (e.g., spinach, lentils, red meat) to replenish blood loss;
Stay hydrated and include fiber-rich foods to support digestion;
Consider switching to a menstrual cup, which allows you to monitor flow volume more accurately;
Talk to your doctor if symptoms persist or worsen.

In some cases, treatments may include:

Hormonal therapy (e.g., birth control pills);
Nonsteroidal anti-inflammatory drugs (NSAIDs);
Tranexamic acid to reduce bleeding;
Surgical options for fibroids or polyps³⁴.

Menstrual blood clots are a natural part of many people’s cycles. Understanding what’s normal and what’s not empowers you to care for your body with confidence. Whether you’re using a menstrual cup, pads, or tampons, knowing your flow helps you make informed choices and seek help when needed.

Scientific references:

¹ Mayo Clinic.“Blood clots during menstruation: A concern?" https://www.mayoclinic.org/diseases-conditions/menorrhagia/expert-answers/blood-clots-during-menstruation/faq-20058401

² Healthline. “Menstrual Clots: Causes, Diagnosis, Treatment & More" https://www.healthline.com/health/womens-health/menstrual-clots

³ ACOG. “Abnormal Uterine Bleeding" https://www.acog.org/womens-health/faqs/abnormal-uterine-bleeding

⁴ Johns Hopkins Medicine. “Uterine Fibroids". https://www.hopkinsmedicine.org/health/conditions-and-diseases/uterine-fibroids

This blog post is intended for educational purposes only and does not constitute medical advice. If you are experiencing severe or persistent symptoms, please consult a qualified healthcare professional.

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