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    Period blood clots: How to know when to see a doctor

    Updated 23 December 2022 |
    Published 01 October 2018
    Fact Checked
    Medically reviewed by Dr. Ruth Arumala, Obstetrician and gynecologist, gynecologic and cosmetic surgeon, Texas, US
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    Period blood clots don’t happen to everyone who menstruates, but they aren’t all that uncommon either, especially during the heaviest days of your period. Here, we break down what’s happening during your period to cause clots, the size and color to look out for, and when to seek out medical expertise.

    For women and people who menstruate each month, understanding the vast catalog of physical and emotional symptoms that can accompany your period is useful for lots of reasons. For example, they can alert you to any changes in your body or give you time to tweak your schedule so you don’t book a swim session right when your period is heaviest (we’ve all been there). 

    With this in mind, period blood clots can be a tricky symptom to understand. However, these globules of blood and tissue aren’t all that rare. So while it might feel understandably alarming to see a period blood clot or even make you feel a bit squeamish, rest assured — you’re not the only one seeing them from time to time. 

    So how can you decode what a blood clot might mean? We chatted with Dr. Sara Twogood, obstetrician and gynecologist, Cedars-Sinai Medical Group, California, US, to understand exactly what happens to your body during a period, why some people have period blood clots, and when to go see your doctor if you have any concerns.

    Period blood clots: Key questions

    First things first: Before we take a deep dive into period blood clots, let’s do a quick refresher on what a period actually is. “A period is when the lining of the uterus (the endometrium) bleeds and sheds,” explains Dr. Twogood. “The blood (along with some tissue of the endometrium) has to leave the body through the cervix (the canal that connects the uterus to the vagina) and then the vagina.” 

    Sometimes, you might find period blood clots in the toilet in addition to your usual flow. Let’s take a closer look to find out more.

    What causes period blood clots?

    So, why do period blood clots form? Essentially, it’s all related to your body being incredibly clever. To stop you from losing too much blood during your period, the plasma and platelets in your blood join forces to create blood clots that form in your uterus; this is completely normal. It also explains why you’re more likely to get period blood clots alongside heavy bleeding: Your body is working hard to prevent excessive bleeding by creating the clots.

    Other causes of period blood clots

    There are other potential medical causes of period blood clots that you may wish to investigate. Just remember that while it’s helpful to be aware of what period blood clots can mean, only your doctor can diagnose you with any of the below issues, so try not to worry too much before booking an appointment.

    What does a period blood clot look like? 

    To save you from manically searching for “period blood clot pictures” online to compare and contrast, we’ve had a scroll through Flo’s Secret Chats to see how Flo users describe the range of period blood clots they’ve experienced, in terms of color, size, and consistency. If you’re noticing jelly-like or stringy blood clots during a period, rest assured; you’re in good company.

    Some Flo users compare blood clots to sea creatures, with more than one likening their texture and appearance to jellyfish (e.g., “the clots feel like jellyfish”; “feels like I’m birthing jellyfish”). Others describe them as a breakfast staple, with one user saying the blood clots in their period are like “clumps of strawberry jam” (apologies if you had jam for breakfast this morning).

    As well as consistency, period blood clots can vary in color, too, just like your period blood color. Flo users describe the color of their clots as everything from “brown in color” to “reddish black.” Experts note that period blood clots “may appear red, pink, brown, or even rust-like” in color, and interestingly, the color of the clot tends to be related to how quickly it has moved through your body. “Bright red usually means it was passed quickly, while the darker colors can mean the blood was exposed to oxygen inside the vagina and oxidized on its way out,” explains Dr. Twogood.

    Are you also seeing bits of white in your period blood clots? “The tissue and cells that are seen in clots are the endometrial tissue itself that is combined with blood during a period,” Dr. Twogood explains. So there’s no need to worry. Period blood clots with white tissue are generally completely normal.

    Now, for size: How big can you expect a period blood clot to be? As a general guideline, Dr. Twogood says that “small blood clots (such as the size of a quarter or smaller) can be normal.” In comparison, period blood clots larger than a quarter (that’s roughly an inch) are not considered typical. If you think yours are on the larger side of this scale, it’s best to reach out to a doctor so they can look into it for you.

    Are period blood clots normal? 

    Rest assured that it can be normal to pass blood clots during your period. In fact, one study found that just over half (54%) of women with periods experienced blood clots. So you’re certainly not alone if you do discover period blood clots in the toilet or on your pads or tampons.

    When might you need to see a doctor? 

    If you’re feeling concerned about the size, shape, or number of clots you’re passing during a period, try not to panic. Dr. Twogood advises trying to quantify the clots and total blood loss and then talking through this information with a health care professional. You can use an app like Flo to help you track period symptoms like these.

    In particular, Dr. Twogood recommends seeking medical help if you notice any of the following symptoms: 

    • “Regularly passing period clots larger than an inch in diameter (such as several in a period and multiple periods in a row)”
    • “Bleeding through a tampon or pad in less than an hour”
    • “Having to change period products multiple times in the middle of the night”
    • Symptoms of anemia, like significant fatigue, weakness, dizziness, or frequent headaches (as anemia can be a sign of significant blood loss)”
    • “Pain that gets in the way of normal daily activities and is not alleviated by common measures like over-the-counter medications or lifestyle changes”

    Remember that you can always book a checkup if you’re concerned or unsure about what’s typical and what isn’t.

    How should you treat period blood clots? 

    If you’re finding it difficult to soothe any pain associated with period blood clots, or they’re interfering with your life, then treatments are available, but you need to determine what’s causing the clots first. Your doctor can help determine this by talking through your medical history with you. They may also need to do some extra tests, such as physical examinations, scans, blood work, and hormone checks.

    Dr. Twogood gives the following examples of possible medical treatments for period blood clots that your health care provider may bring up in conversation with you:

    • Hormonal medications, such as birth control pills 
    • Hormonal intrauterine devices
    • Over-the-counter medications like ibuprofen and naproxen
    • Prescription nonhormonal medications, such as tranexamic acid
    • Occasionally, surgical procedures 

    Period blood clots: The takeaway

    Experiencing blood clots while on your period isn’t uncommon, and usually, it’s not a cause for concern. Even if blood clots during a period are accompanied by some pain, there isn’t necessarily any need to worry.

    However, there are certain situations in which you may want to start logging your blood clots with your periods. This could relate to blood clot size (if you’re regularly seeing golf-ball-sized period blood clots, for example, take note) or other symptoms you may be experiencing, like those associated with heavy bleeding or anemia. 

    If you’re worrying about questions such as “how many blood clots are normal during my period?” it might help to start tracking your menstrual symptoms and cycles. You can use a period tracker like Flo since you can note down flow intensity and log any premenstrual syndrome symptoms on it. This helps you understand what typical looks like for you and means you can clock any changes to your period from one month to the next.

    Experts recommend that you see a doctor for blood clots during a period if you’re experiencing excessive bleeding or if your period is accompanied by pain that gets in the way of daily activities. Your doctor should be able to reassure you if you have any concerns by prescribing medications and ruling out any other issues that may be causing blood clots during your period. 


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    History of updates

    Current version (23 December 2022)

    Medically reviewed by Dr. Ruth Arumala, Obstetrician and gynecologist, gynecologic and cosmetic surgeon, Texas, US

    Published (01 October 2018)

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