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Painful Period With Blood Clots: 5 Main Causes and Treatment

By: Author Dr Akatakpo Dunn, MBBS, PG Dip Ultrasound, Prof Dip O&G (RCPI) Medical Director & Lead Obstetrician/Ultrasonologist, Verah Clinic & Maternity

Posted on Last updated:

Are you experiencing painful period with blood clots? Is this the first time you’re noticing it, or it has been happening for a while now? Are you also bleeding much more than normal during periods?

If you suddenly experience a painful menstrual period, you should not be too concerned if the pain is mild to moderate and similar to what you usually feel. Most women, especially young girls, will get tummy pain during menstruation. However, very severe pain that is new for you, or pain with feeling faint, dizzy or unwell, should be checked by a doctor.

This pain feels like your belly is contracting and occurs because hormone forces your uterus to contract, thereby expelling menstrual blood through your vagina. 

Ordinarily, while some women will experience mild to moderate cramps during periods, some other women may be unlucky and experience very severe pain in their abdomen.

Are blood clots normal?

During menstruation, it’s not abnormal that you will have blood clots coming out of your vagina. Usually, your body breaks down blood clots through fibrinolysin, an enzyme that ensures that your period does not contain clots.

However, if you start having a heavy flow, it becomes difficult for fibrinolysin to completely break down clots, resulting in blood clots you may see sometimes.

The truth is, it’s not entirely abnormal that you get to see small clots in your period. This is usually common in the first or second day of menstruation as the flow is heavy. Towards the end of your period, you will notice bleeding is not so heavy without clots.

Having said that, if you have a painful period with big clots, it could signify something more serious. Doctors usually get more concerned if:

  • Your period lasts more than 7 days,

  • You are soaking a pad or tampon every 1–2 hours for several hours, or

  • You are passing blood clots bigger than a grape (about 2–3 cm) many times in a day.

Common causes of a painful period with clots are uterine fibroids, vaginal infections, endometriosis, adenomyosis, pelvic inflammatory disease and cervical stenosis. Bleeding disorders and some hormonal problems can also cause heavy periods with clots. 

On the other hand, pain threshold during menstruation will vary from woman to woman. In some women, the pain will not be severe and can easily be controlled with over-the-counter medications. While in others, pain may even require hospitalization.

In fact, women that are under the age of 20 will experience much more painful period. If your mother or sister also have very painful menstruation, it’s likely you will feel such pain too. However, if you suddenly start having much more painful periods after your mid-20s or 30s, especially with clots or very heavy bleeding, doctors will want to rule out conditions like fibroids, endometriosis or infections.

Then again, after childbirth, women that usually had intense period cramps, will notice less pain during periods.

This article explains causes of painful menstruation with blood clots, and when you must inform your doctor.

What causes painful period with blood clots?

1. Normal menstruation

It’s common to panic when you get to see clots coming through your vagina during your period. However, you should not. Your body works by breaking down blood clots naturally and quickly before it comes out through your vagina.

Sometimes, during the first days of period, menstrual flow might be heavy, resulting in small blood clots in your period.

What to do?

Don’t panic yet. It’s important you observe the size of clots and when they occur. Furthermore, you should monitor the length of your period too.

For most women, a normal menstrual period will last between 2 and 7 days. This implies that, if your period is now lasting longer than usual for you, or more than 7 days, it could be a sign of something wrong.

Also, if you notice big blood clots coming from your vagina (bigger than a grape or coin), or you are changing pads every 1–2 hours, surely, something is not okay. Quickly inform your doctor, as this level of bleeding can cause anemia and may need treatment.

2. Uterine fibroid

If you experience a painful period with blood clots, it could be due to a large uterine fibroid. Uterine fibroids are benign growth within and outside the uterine muscle.

Depending on where a fibroid grows in the uterus and the size, it may cause serious symptoms. One major problem with uterine fibroid is vaginal bleeding.

A fibroid can be found outside the uterus (subserosal fibroid) or attached to the out side of the uterus (pedunculated fibroid) or within the muscle of the uterus (intramural fibroids). Fibroids can also grow just under the lining of the womb and bulge into the cavity (submucous or submucosal fibroids). These submucous fibroids are strongly linked to heavy period bleeding and passing clots.

Women that have fibroids, especially the submucous type, are more prone to vaginal bleeding with clots.

So what causes women to have fibroids?

If you are experiencing a prolonged period that won’t stop after seven days, there is a chance you have a fibroid, but other causes of heavy bleeding are also possible (such as hormonal imbalance, adenomyosis or bleeding problems). The exact reason why fibroid grow is still not very clear, though there is an increased risk if:

  • You are black (fibroid are more common in black women than Caucasians)

  • You experience very early first-menses (before the age of 11)

  • You are overweight or obese

  • Your mother or sister has been diagnosed of a fibroid

To be frank, about 70 percent of women will have had a fibroid before the age of 50. However, most of these women will not get any symptoms.

In symptomatic women, here are some signs to watch out for:

If you have these symptoms, talk to your doctor. Treatment will depend on the size and position of the fibroid, your symptoms, and if you still want children. A large uterine fibroid may need surgery, but many women can be managed first with medicines (like NSAIDs, tranexamic acid or hormonal methods, including some intrauterine devices) or other procedures such as uterine artery embolization. Your gynecologist will guide you on the best option.

3. Endometriosis

Endometriosis is a common cause of painful period with blood clots.

Endometriosis means tissue similar to the endometrium that covers inside of the uterus is now settled in different parts of your body. Commonly, it can be found in the ovary, fallopian tubes, abdomen, vagina, and cervix. This tissue still reacts to your hormones each month, which is why pain can be severe.

Endometriosis is quite common (affecting around 10 percent of women of reproductive age), though some women will not have symptoms at all, while many have significant pain or fertility problems.

Symptoms of endometriosis are:

  • Painful periods

  • Pain during sexual intercourse

  • Chronic pelvic pain before period and after period

  • Severe low back pain

  • Diarrhea or painful bowel movements around your period

  • Painful urination, especially in your period

  • Infertility

If you have these symptoms, talk to your doctor. During your clinic visit, your doctor will clinically examine your abdomen; sometimes a mass may be felt.

Other tests to help in diagnosis are abdominal or transvaginal ultrasound, laparoscopy, and blood tests.

Treatment is through pain medications and hormonal treatments (such as combined pills, progestin-only methods or other hormone injections or coils). Sometimes surgery is needed. At the moment, there is no permanent cure for the disease, but symptoms can often be controlled and fertility improved. You can read more on the ACOG endometriosis FAQ or Mayo Clinic endometriosis page.

4. Adenomyosis

Covering the inner surface of the uterus is the endometrium. The endometrium can be forced into the uterine muscle resulting in pain. This is called adenomyosis and usually cause painful menstruation in women.

If you are already in your 40’s and have children, it’s possible your painful period are due to adenomyosis. Risk factors are childbirth and cesarean section or other surgery to the womb.

Other symptoms (apart from painful menstruation) are:

  • Prolonged periods (lasting more than 7 days)

  • Pain during intercourse

  • Massive blood loss during period with blood clots

  • A bulky, tender uterus on examination

Treatment is by Non-Steroidal Anti Inflammatory Drugs (NSAIDs), oral contraceptive and other hormonal treatments (including levonorgestrel intrauterine system). In severe cases or when childbearing is complete, surgery to remove the uterus (hysterectomy) may be advised. For more information, see Cleveland Clinic’s adenomyosis page or Mayo Clinic’s adenomyosis overview.

5. Vaginal infections

Pelvic inflammatory disease is a consequence of poorly treated vaginal or sexually transmitted infections. Women with vaginal or pelvic infections are prone to experience irregular menstrual bleeding with lower tummy pain.

Symptoms of pelvic infections are:

Vaginal itching and soreness of the vulva are more common with infections like yeast (candida) or some other vaginal infections, which can also cause discomfort and spotting.

If you have severe lower tummy pain with fever, foul-smelling discharge, or pain during sex, you should see a doctor or go to a clinic urgently. Pelvic inflammatory disease, if not properly treated, can cause infertility and chronic pelvic pain. You can read more in the CDC fact sheet on pelvic inflammatory disease or Cleveland Clinic PID page.

Worried why you have painful menstruation with blood clots? Ask Us!!! This article is for general education only and does not replace a physical examination by your doctor or gynecologist.

You can read more in ACOG’s FAQ on heavy menstrual bleeding and this Mayo Clinic page on blood clots in periods.