Having a period means that your vagina might unleash clots of blood that look nothing like the tidy little splashes of fluid you see in most tampon commercials. While period clots can be part and parcel of menstruation, sometimes they can be a sign that something isn’t quite right in your body. Here’s how to know the difference.
Period clots usually form if you have a really heavy flow.
First, a mini-primer on blood clots in general.
When you think about clots of blood, you might imagine the kind that come together when you have a cut. Your body springs into action, combining enough platelets (blood cells that adhere to each other) and proteins from plasma (the liquid part of your blood) to plug the injured blood vessel, the Mayo Clinic says. This is how clots help to stop bleeding.
Blood can also clot together in your veins, especially if you have risk factors like being pregnant, which causes hormone changes that increase your blood clot risk, or recently having had surgery, because moving less also contributes to this hazard. These clots can dissipate without harm, but sometimes they can be life-threatening.
The blood clots that can emerge from your vagina during your period are a bit different than these other types, though. Period clots are comprised of the endometrial lining that builds up in your uterus in preparation for pregnancy, then sloughs off during your period when you don’t conceive.
“Clots are normal, but they typically happen when a [person] has a heavy flow,” G. Thomas Ruiz, M.D., lead ob/gyn at MemorialCare Orange Coast Medical Center in Fountain Valley, California, tells SELF.
This is in part because a gushing period prompts your body to form clots so you don’t lose more blood than you should (around two to three tablespoons over the course of your entire period). Also, the opening of your cervix (the narrow passage at the lower end of your uterus) is pretty small. If you have a substantial flow, that allows the blood to build up in your uterus, Dr. Ruiz explains, giving components like platelets and plasma proteins time to congeal.
If your period clots are bigger than a quarter, see your doctor.
For the most part, period clots are a completely normal part of menstruation, Mary Jane Minkin, M.D., a clinical professor of obstetrics and gynecology and reproductive sciences at Yale Medical School, tells SELF.
But if you’re seeing clots the size of a quarter or larger, you should visit your doctor, according to the Centers for Disease Control and Prevention (CDC).
“If someone is passing quarter-size clots, that tells me that there could be something wrong [in] the uterus that needs further investigation,” Dr. Ruiz says. You can even take a picture of what you’re seeing so that your doctor can look during your visit. “It helps show me the magnitude of what’s been going on,” Dr. Ruiz says.
- You’re soaking through one or more tampons or pads every hour for multiple hours in a row.
- You need to use two pads at a time.
- You have to change your pad or tampon during the night.
- You bleed for more than seven days.
- Your flow is so heavy that it sometimes prevents you from living your normal life.
- You regularly experience pelvic pain (especially in your lower abdomen) during your period.
- You’re constantly fatigued.
A few health conditions could be behind such large period clots.
One major possibility is polycystic ovary syndrome (PCOS), a hormonal disorder that can cause incredibly heavy periods, according to the Mayo Clinic. This is because the hormone imbalance involved can prevent you from menstruating for some time. When your period does finally arrive, you may have accumulated many months’ worth of blood.
Endometriosis is another potential reason behind huge period clots. At this point, the general medical consensus is that endometriosis happens when the tissue that lines your uterus (endometrium) begins to grow on other organs. However, as SELF previously reported, some experts believe there may be other causes behind this condition. One theory is that people with endometriosis grow misplaced tissue that is similar to the endometrium, but that it responds differently to hormones. No matter the cause of endometriosis, frighteningly heavy bleeding is one possible symptom.
Yet another issue behind heavy bleeding that can cause large clots is adenomyosis, a condition where your endometrial tissue spreads into the walls of the uterus, according to the National Institutes of Health (NIH).
There’s also a chance that large “period” clots actually indicate a miscarriage you’re undergoing without realizing you were pregnant. A miscarriage is a pregnancy loss within the first 20 weeks of pregnancy, the CDC explains. After that, a pregnancy loss is known as stillbirth.
If you have large period clots, be on the lookout for other symptoms of these health conditions.
Even though a variety of health conditions may cause clots larger than quarter-sized, they usually have other characteristics that give them away.
Endometriosis is notorious for debilitating pelvic pain, especially during sex or while using the bathroom when you have your period. (Though you should know that this pain can strike at any time.)
Adenomyosis can also cause pelvic pain, and it may make your lower abdomen feel swollen, tender, or like it’s under some kind of pressure, according to the Mayo Clinic.
Along with heavy, long, and painful periods, fibroids can lead to a constant urge to pee, feeling like you can’t fully empty your bladder when you do urinate, constipation, and even back or leg pain, the Mayo Clinic says.
Since both periods and miscarriages can cause bleeding and cramping, it may be hard to tell the difference between the two, depending on your situation. Your doctor should definitely be able to help determine if what you thought were period clots are actually a sign of miscarriage. It’s important to give them any relevant information, like if you are sexually active and usually don’t experience heavy periods or large clots except for now. Also, if you think there’s a chance a clot could be tissue you’ve miscarried, the Mayo Clinic recommends putting it into a clean container and taking it to your doctor’s office to know for sure.
Additionally, be sure to mention symptoms like weakness to your doctor. While that may not point them to the cause behind your clots, it could be a sign that you’re dealing with anemia due to your heavy bleeding, the CDC says.
Doctors can typically treat intense bleeding that causes large period clots with hormonal birth control that contains progestin to thin your uterine lining, Dr. Minkin explains. The main exception here is for miscarriages. If it turns out that what seemed like a clotty period is a pregnancy loss, your doctor will need to run tests to make sure all the tissue has been expelled from your uterus so it can’t cause an infection, then remove any remaining tissue if necessary.
Regardless of what’s behind your heavy bleeding, as Dr. Minkin points out, you can’t get help if you don’t tell your doctor what’s wrong.