Blood Clots During Period – Causes, Signs, Risks, Diagnosis


As a woman, you may experience some embarrassing – and sometimes gross – things during your period. Uncomfortable as it is to talk about, changes in the heaviness of your flow and clots can be an indication that something is wrong.

Before you start panicking, know that it’s normal to see clots on your heaviest days. It’s the size of the clots that you should be concerned about. We’ll explain what causes clots and when you should be concerned about them during your period.

What Causes Blood Clots?

In general, blood clots can be caused by a variety of things, including:

  • Family history
  • Heart arrhythmias
  • Antiphospholipid syndrome
  • Arteriosclerosis
  • Factor V Leiden
  • Deep vein thrombosis
  • Polycythemia vera
  • Peripheral artery disease
  • Obesity
  • Heart attack
  • Heart failure
  • Pregnancy
  • Certain medications
  • Surgery
  • Smoking
  • Pulmonary embolism

That’s quite a long list of potential causes. Clots that form in the small veins close to the surface of your skin are generally harmless, but if clots break away from their original source, they can cause health issues (some life-threatening).

Are Menstrual Blood Clots Normal?

Yes, they can be. Most women will experience clots during their period at some point in time. Many women pass small clots as a normal part of their period.

However, when clots are larger than a quarter in size, you should see your doctor as this is an indication of a potential medical issue.

Signs of Period Blood Clots

What are period blood clots? How do you know if you’ve passed clots?

Period blood clots are:

  • Most common during the first few days of your period – the heaviest days.
  • A thick mass of blood. Clots often look like jam.

Clots can vary in consistency and color. They’re typically dark or bright red, and they may make your flow thicker or denser.

Most clots are small in size  and are usually only present during the first few days of menstruation. If you’re still seeing clots towards the end of your period, there may be an underlying medical issue that needs immediate attention.

What Causes Large Blood Clots During Period?


During menstruation, the lining of your uterus sheds – sometimes at a rapid pace. When you start bleeding, anticoagulants are released to help break down your flow before it leaves your body. But during your heaviest days when your flow is thicker than normal, blood is expelled from your body at a much faster rate. When this happens, the anticoagulants don’t have time to work, and clots can form.

Clots that are larger than a quarter are often an indication of heavy bleeding and may be a symptom of a medical issue.

Causes and Risks of Heavy Bleeding During Period

If you experience a heavy period with clots, see your doctor as soon as possible.

What’s considered heavy bleeding?

  • Soaking through a pad or tampon every 2 hours
  • Passing blood clots that are larger than a quarter
  • Menstrual bleeding that lasts longer than 7 days

If left untreated, heavy bleeding can eventually cause anemia, a condition that causes weakness and fatigue.

Causes of Heavy Bleeding

  • Hormone imbalances
  • Uterine fibroids or polyps
  • Certain birth controls, like IUD devices
  • Uterine or cervical cancer
  • Pregnancy issues, such as a miscarriage or ectopic pregnancy
  • Bleeding-related illnesses and diseases
  • Other diseases and illnesses, including thyroid disease, PID and cancer
  • Certain medications, such as aspirin, which can increase bleeding

Diagnosing Heavy Bleeding

Blood on white background.

It can be difficult to diagnose heavy bleeding as each person has a different idea of what “heavy bleeding” is.

Under normal circumstances, bleeding lasts about 4-5 days, and only 2-3 tablespoons of blood is lost. However, women with heavy bleeding will bleed for 7 days or more and lose twice the normal amount of blood.

If you find yourself having to change your pads and tampons every two hours or more often, you need to see your doctor right away.

Your doctor might ask you a series of questions to diagnose heavy bleeding, such as:

  • How long does your menstrual cycle typically last?
  • When did you get your first period?
  • How many days would you say you experience heavy flow?
  • How many days does your period last?
  • Is your period affecting the quality of your life?
  • Does anyone else in your family suffer from heavy bleeding?

If you’re unable to answer some of the questions above, your doctor may ask you to track your periods in a journal. Write down the dates of your period and the heaviness of your flow in this journal.

If your doctor suspects that you might have a bleeding disorder or other medical condition, he or she may recommend getting the following tests:

  • Pap test: Cells from your cervix will be examined to see if you have inflammation, an infection or cancer is causing the issue.
  • Blood test: A blood sample will be checked for thyroid issues, anemia, or other issues that affect blood clotting.
  • Ultrasound: An ultrasound will let your doctor check your blood flow.
  • Endometrial biopsy: Samples from your uterus will be taken to see if you have abnormal cells or cancer.

Do Blood Clots Need to Be Treated?

In most cases, blood clots are completely normal during your period and don’t require any treatment.

blood clots during period

But if you’re passing clots that are larger than a quarter or are soaking through your pads or tampons quickly, your doctor may recommend a variety of different treatments to remedy the problem. If left untreated, it could lead to serious or life-threatening medical issues.

Common treatments for heavy bleeding include:

  • Ibuprofen: Reduces bleeding and menstrual cramps.
  • Iron supplements: If you’re showing signs of anemia, your doctor will recommend taking iron supplements to ensure your blood is carrying enough oxygen.
  • Birth control: For some women, birth control can regulate and normalize periods.
  • Hormone therapy: May be recommended if hormonal imbalance is the cause of heavy bleeding.
  • IUC: A contraceptive device that is placed into the uterus. An IUC can regulate periods and reduce bleeding.
  • D&C (Dilation and Curettage): A surgical procedure that removes the top layer of the uterus to reduce bleeding.
  • Hysterectomy: Only recommended in severe cases. This procedure removes the entire uterus. After a hysterectomy is performed, you can no longer get pregnant and will not get your period.

Heavy bleeding is a common issue that many women face. If any of the symptoms apply to you, you’re not alone. But there is help out there, and you don’t have to let your period affect the quality of your life. If you’re passing large clots and bleeding for more than 7 days, see your doctor to get treatment and prevent complications in the future. Remember, clots are normal, but if they’re larger than a quarter, you should see a doctor right away.


  1. My 69 year old lady friend has a grapefruit-size blood clot atop the uterus, resulting in constant pain. What are the implications?

  2. i’m young lady 32 years old ,i’m having problem when i sse m period i bleed too much and having quater of clots and i det tired every month and i use 3 packets of peds which are 10 inside,i consulted a gynea he suggested i must use depo injection which i did and i was not seeing my period at all and my skin colour changed it was too black,so i need help cause every month i expriencing same problem

  3. my wife has heavy bleeding with too much pain at the abdomen and on her back, the leeding may last for five days or more. please help me to with to know the right medicine, she is not pregnant.

  4. Am 22,I had heavy bleeding After my period 4 months ago with pains,which I consulting a gynaecologist and j later stopped.since then,av been experiencing same pain and heavy cloths every months,somethings I use 2-3packs of pad …. What do I do

  5. I’m 42 yrs old never had children. I have had lengthy periods in the past when I was younger. Normally there about 7-10 days this time I’m going on 21 days not all days have been heavy. I have passed some really big clots on the heavy days which I have in the past just not this much. When I pass the clots I have some slight cramping nothing to terrible. Last month was super crazy work wise working all 3 shifts in a week. I can’t even remember if I had a period or not. Could my hormones and stress be a factor.

    • It is not uncommon for physical stress (or even athletic activity) to cause an avg. woman to miss a cycle. Some high intensity female athletes even have their cycles completely stop during training.

  6. I have 7cm fibroid I get heavy bleeding for 7 8 days and I get cloths in urine during period ,if I eat no veg I get more veg not much my bed sheet dress all I get and tired what to do

    • Hi did you ever go back to the doctor to find out what the problem was and did your flow ever stop? I’m experiencinh something with the exact symptoms i’d be really greatful if you replied. Thanks

  7. im 20 yrs recently i miss my period for 2 months i take about 5 home pregnancy test and 2 from the hospital all came out negivitive….my period end up coming and its on me for a month and a half now im getting heavy bleeding with big blood clots….im not getting any pain but im getting large clots 4 or 5 times a day….have to change my pad every 2 hrs or less…doctor take blood test and everything good im so frustrated cus this is the first time this is happening….

    • I would not be r overly concerned or panicked the first cycle this happens (especially after missing a couple of cycles), but if it happens with any sort of regularity then I would be back at the doctor’s office insisting on a good explanation as to why it is occurring (even if you need to switch docs to find one willing to figure out why).

      Many OB/GYNs are very focused on reproduction, and have the attitude that if you’re done with that, or things are not working right – you should yank the plumbing (hysterectomy) – but that has its own serious side effects (especially in sexual response & pleasure), and so that should always be the last resort (not the first) when trying to solve problems in your reproductive system.

    • Hi did you ever go back to the doctor to find out what the problem was and did your flow ever stop? I’m experiencinh something with the exact symptoms i’d be really greatful if you replied. Thanks

    • i have small clots period but its not not my date period actually its supposed to be on 13 but i got my blood clots this fist week 4 its been 2days im scared plss do reply

  8. I’ve been having pain since Saturday in the morning and I’ve been bleeding ever since Sunday I went to hospital and they said they didn’t find nothing. They also gave me birth control and ibuprofen but it’s not working. Today the bleeding and the pain got worse

  9. I am 31 years of age my question is if u done had surgery of having polyps or fibroids removed from being laser is it a possibility they can come back the reason for the question because I had it done this year in February and after my surgery I had a cycle a couple of weeks after it and it went ok but then I didn’t have no menstrual for about 4 months until the end of September and now it’s still on now I am having heavy bleeding and having blood clots bigger than a quarter every time I use the restroom and for my pads I change them every two hours and going threw pads so what do i dp

  10. 25 years old .ttc for 3 months. 5 days period and severe lower back pain every month. Blood clots during peeing not on the pad . .no blood on the pad

  11. I am 23 years old and have polycystic ovaries. Have done since I was younger. And have always had heavy periods with a lot of pain. However I am currently having my 3rd period within 6 weeks. The pain gets worse with each one, and the flow is getting heavier. The first day I came on this time I bled through a super tampon within an hour. And the clots are getting bigger and bigger everyday. I’m not sure what to do. As the biggest clot was probably an inch in length. But they’re getting bigger and more of them.

  12. Im haveing blood cloths the size of a baby comeing out the vaginal area here my peruod lasted a month and here I’m bleeding again I’m afraid cuz I don’t nie what to do I keep changing pads every half an hour what should be happening

  13. Im haveing blood cloths the size of a baby comeing out the vaginal area here my peruod lasted a month and here I’m bleeding again I’m afraid cuz I don’t nie what to do I keep changing pads every half an hour what should be happening I’m 38 yes old and I’m scared

  14. I am 39/year old who had irregular cycle in my early teens to twenties. But after I gave birth, it become normal cycle. At times my cycle is even shorter 3-5 days. But recently I missed my periosexthen it appeared 15 days later. I begin to spot followed by clots bigger than quarter size. I thought might be miscarrying but I an not having sex. I was on antibiotic could that cause heavy bleeding.

  15. Can someone gove me advice ? For the last 2 months (December & January) i had spotted approximately 3 times for like 4 days each. I finally got a reg period febuary 1st, so i thought. But now im bleeding really heavy and my blood clots are like 2 quarters.. I took a pregnancy test in December and January but, both was negative. Thank you in advance ❤

  16. I missed my period for the pasted 2 months or so and just recently got my period again. And is it normal to clot very large clots on your 2nd day when normally it’s closer to your last day?

  17. Hello, I’m just turning 18,
    I found this website because I’ve been experiencing for a long time now, heavy flow with lots of tiny blood clots, what I mean by heavy, like, it comes for about 7-10 (maybe even more some times) days then leaves for a couple and then come backs, or sometimes it won’t show up for about a week and then it’s back again and it’s heavier then before, I’ve never had this problem before, it’s been going on for about three-four months,
    The tiny blood clots I’ve been noticing more and more, they looks like veins but more clotted (so sorry for the details)
    I’ve been having cramps and it hurts to walk and stinging pains, (about a year ago I barley had cramps or even much of a heavy flow or messed up flow like I do now, it use to be perfect and on time) now it’s like a rebellious teenager,
    About a year ago I was diagnosed with what they call a molar pregnancy, super uncommon,
    I went threw the steps the doctors prescribed, did the chemo treatments (I was stage two when they found it)
    I knew my period would probably not be normal after it all,
    But lately with this I’ve just been really starting to panic and get worried,

  18. Hi, i’m 28 and started experiencing more than a quarter clot in my period late last year with my period occurring twice a month now, I’ve seen a gynecologist and he prescribed some drugs conducted some test which made my period normal and now its back cos i’m presently bleeding for d second time this month and i’m worried

  19. I spotted for like 4 days a week and a half ago, and a week and a half before that I sported for about the same amount of time. I started bleeding yesterday and passed a massive blood clot, bigger than I have ever seen and I have had 4 children. Should I be concerned?

  20. My periods are starts normal time & it last for 3-4 days. but this time i am getting more blood clots and i have a light discomfort in lower back (its pain kind.) the earlier month period was normal without any blood clots. but this time after 3 days also iam getting the blood clots. Can you pls. suggest what could be the reason

  21. I am 41 with 2 children. I had a tubal ligation after my second child. My periods are regular, however I have always struggled with them. When I was younger I was put on birth control to help with them. I have always been a heavy bleeder and had medium size clots, so many of them that I became anemic and would get very sick every month, hence the reason for the birth control. Now that I’ve had children, I have found that my period fluctuates in heaviness and also changes the time of the month that it comes about every 3 months. It gets earlier by about 4 days. During that 3rd month, I usually end up at the hospital ER due to severe pain and needing IV fluids. I am noticing a larger amount of clots and when the last ultrasound was done 2 years ago, the doctor did say I had a large number of clots. I am noticing between 25-30 nickel sized clots about every 3 months. Is this normal

  22. Hi, 2 months back I had unprotected sex and I was on contraceptives e which was on the 23rd of June and in July had my periods and I stopped with the contraceptives.I did take a urine pregnancy test 4 weeks after I had sex and it came out negative.This month I had my periods on the 7th and yesterday (4days early to my 28 days cycle). Last week I went to the pharmacy and did a blood pregnancy test and it also came out negative. I don’t have any symptoms of pregnancy other than being hungry which I thought was from the contraceptives I was using. Should I be worried ?.

  23. Yesterday, my period came 10 days early and I expelled 7 golf ball sized blood clots (they looked like raw chicken livers) over the span of about 10 hours. There was no pain. I normally have 2 heavy period days during my regular 7-day period cycles and occasionally have some small clots. I am 48 y/o. Is this cause for concern?


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