Blood Clots During Periods: Know What Is Normal Vs Abnormal

Many women notice blood clots during their menstrual periods and wonder whether they are normal or a sign of an underlying health problem.

Seeing clots in menstrual blood can be alarming, particularly if they appear suddenly or become larger than usual.

In most cases, however, small menstrual blood clots are a normal part of the body’s natural process of shedding the uterine lining.

Menstrual blood is made up of blood, uterine tissue, cervical mucus, and cells from the endometrium.

During heavier menstrual flow, the body’s natural anticoagulants may not have enough time to prevent blood from clotting before it leaves the uterus.

As a result, small jelly-like clots can appear, especially during the first one or two days of a period.

While occasional small clots are generally harmless, passing large clots, experiencing severe pain, or having very heavy menstrual bleeding;

may indicate an underlying condition such as uterine fibroids, adenomyosis, endometriosis, polyps, hormonal imbalance, miscarriage, or a bleeding disorder.

Recognizing the difference between normal and abnormal menstrual clots can help you know when to seek medical advice.

As a physiotherapist, I frequently work with women whose heavy or painful periods affect their daily activities, exercise tolerance, and quality of life.

Although physiotherapy cannot eliminate menstrual blood clots directly,

it can help manage associated pelvic pain, improve mobility, reduce muscle tension, and support overall pelvic health as part of a comprehensive treatment plan.

Understanding why menstrual clots occur and when they may signal a medical condition is an important step toward protecting your reproductive health.

Evidence: The American College of Obstetricians and Gynecologists (ACOG) recommends evaluating women who experience heavy menstrual bleeding, large clots, or symptoms affecting daily life to identify underlying causes and provide appropriate treatment.

What Are Blood Clots During Periods?

Menstrual blood clots are thick, jelly-like collections of blood, tissue, and proteins that are expelled from the uterus during menstruation.

They may appear:

• Bright red
• Dark red
• Brownish-red
• Soft and gelatinous
• Small or occasionally larger

Most menstrual clots are made up of:

• Blood
• Endometrial tissue
• Fibrin proteins
• Cervical mucus

Small clots are especially common during the heaviest days of menstruation.

Are Blood Clots During Periods Normal?

Yes. Small blood clots are usually considered normal when:

• They are smaller than approximately 2 – 2.5 cm (about the size of a coin).
• They occur only during heavy flow days.
• They are not associated with severe pain.
• They occur occasionally rather than every cycle.

The body’s natural clot-dissolving substances usually prevent clot formation,

but during heavy bleeding they may not act quickly enough, allowing clots to develop before the blood leaves the uterus.

Common Causes of Blood Clots During Periods

Heavy Menstrual Bleeding (Menorrhagia)

Heavy bleeding is the most common reason for menstrual clots.

Larger amounts of blood flow more quickly, giving natural anticoagulants less time to work.

Hormonal Imbalance

An imbalance between estrogen and progesterone can cause excessive thickening of the uterine lining.

When this thicker lining sheds, heavier bleeding and clots may occur.

Uterine Fibroids

Fibroids are non-cancerous growths in the uterus that can increase menstrual bleeding and cause larger blood clots.

Other symptoms include:

• Pelvic pressure
• Frequent urination
• Heavy periods
• Lower back pain

Adenomyosis

In adenomyosis, the uterine lining grows into the muscular wall of the uterus, leading to:

• Heavy periods
• Large blood clots
• Severe menstrual cramps

Endometriosis

Although endometriosis primarily causes severe pelvic pain, some women also experience heavy menstrual bleeding with clots.

Uterine Polyps

Polyps are small growths in the uterine lining that may contribute to irregular or heavy bleeding.

Pregnancy Loss

Blood clots accompanied by severe cramping during early pregnancy may indicate miscarriage and require immediate medical evaluation.

Bleeding Disorders

Inherited or acquired bleeding disorders can increase menstrual bleeding and clot formation.

Normal Menstrual Clots vs Abnormal Blood Clots

Feature	Normal Clots	Abnormal Clots
Size	Smaller than about 2 – 2.5 cm	Larger than about 2.5 cm or frequent large clots
Frequency	Occasional	Every cycle or increasing over time
Timing	During heaviest flow days	Throughout the period or unexpectedly
Pain	Mild or none	Severe pelvic pain or cramping
Blood Loss	Normal menstrual flow	Very heavy bleeding, soaking pads quickly
Medical Review	Usually unnecessary	Recommended to identify the underlying cause

Evidence: Menstrual clots are common during heavy menstrual flow, but persistent large clots or excessive bleeding should be investigated for structural, hormonal, or bleeding disorders. (Cleveland Clinic)

10 Warning Signs of Blood Clots During Periods You Should Never Ignore

Although small menstrual blood clots are usually normal,

certain symptoms may indicate an underlying medical condition that requires prompt evaluation.

1. Passing Large Blood Clots Regularly

Passing blood clots larger than approximately 2.5 cm (about the size of a coin), especially during multiple menstrual cycles,

may suggest heavy menstrual bleeding (menorrhagia), uterine fibroids, adenomyosis, or other uterine conditions.

2. Soaking Through a Pad or Tampon Every Hour

If you are soaking one or more sanitary pads or tampons every hour for two or more consecutive hours,

this is considered excessive menstrual bleeding and should be assessed by a healthcare provider.

3. Severe Pelvic Pain or Cramping

Painful periods accompanied by large blood clots may be associated with:

• Endometriosis
• Adenomyosis
• Uterine fibroids
• Pelvic inflammatory disease (PID)

Persistent or worsening pain should never be ignored.

4. Feeling Weak, Dizzy, or Faint

Heavy menstrual bleeding with frequent blood clots can lead to iron-deficiency anemia.

Symptoms include:

• Fatigue
• Dizziness
• Shortness of breath
• Pale skin
• Rapid heartbeat

5. Bleeding Lasting Longer Than Seven Days

Periods lasting longer than one week, especially with heavy clotting, may require investigation for hormonal or structural abnormalities.

6. Bleeding Between Periods

Unexpected vaginal bleeding or clotting outside your normal menstrual cycle may indicate hormonal imbalance, uterine polyps, infection, or other gynecological conditions.

7. Blood Clots During Pregnancy

Passing blood clots during pregnancy is not considered normal and may indicate miscarriage or another pregnancy-related complication.

Immediate medical assessment is essential.

8. Sudden Change in Your Menstrual Pattern

If you have never experienced blood clots before but suddenly begin passing large or frequent clots, it is important to identify the underlying cause.

9. Heavy Bleeding After Menopause

Any vaginal bleeding or passage of blood clots after menopause requires urgent medical evaluation, as it may indicate serious gynecological conditions.

10. Blood Clots Affect Your Daily Life

If heavy bleeding and blood clots interfere with work, exercise, sleep, social activities, or quality of life, professional medical care should be sought.

Evidence: Women experiencing heavy menstrual bleeding with large clots, prolonged bleeding, or symptoms of anemia should undergo clinical evaluation to determine the underlying cause. (James et al. 2016)

Medical Conditions That Can Cause Blood Clots During Periods

While small menstrual clots are often normal, persistent or unusually large clots may be associated with several medical conditions.

Uterine Fibroids

Fibroids are non-cancerous growths that develop within the uterus and are among the most common causes of heavy menstrual bleeding with clots.

Women may also experience:

• Pelvic pressure
• Frequent urination
• Lower back pain
• Enlarged uterus

Adenomyosis

Adenomyosis occurs when endometrial tissue grows into the muscular wall of the uterus, leading to:

• Heavy menstrual bleeding
• Large blood clots
• Severe menstrual cramps
• Pelvic pressure

Endometriosis

Endometriosis occurs when tissue similar to the uterine lining grows outside the uterus.

Common symptoms include:

• Severe period pain
• Pain during intercourse
• Infertility
• Heavy menstrual bleeding
• Blood clots during periods

Hormonal Imbalance

An imbalance between estrogen and progesterone can cause the uterine lining to become excessively thick, resulting in heavier bleeding and clot formation.

Uterine Polyps

Polyps are benign growths in the uterine lining that can contribute to:

• Heavy periods
• Irregular bleeding
• Spotting between periods
• Blood clots

Bleeding Disorders

Inherited bleeding disorders, such as von Willebrand disease, can increase menstrual bleeding and lead to the passage of larger blood clots.

Miscarriage

In early pregnancy, heavy bleeding accompanied by large clots and severe cramping may indicate pregnancy loss and requires immediate medical attention.

Who Is at Higher Risk of Passing Blood Clots During Periods?

Certain factors increase the likelihood of developing heavy menstrual bleeding with clots.

Risk factors include:

• Uterine fibroids
• Adenomyosis
• Endometriosis
• Hormonal imbalance
• Polycystic ovary syndrome (PCOS)
• Bleeding disorders
• Obesity
• Pregnancy complications
• Perimenopause
• Family history of heavy menstrual bleeding

Having one or more of these risk factors does not necessarily mean you will develop abnormal menstrual clots, but it may increase your risk.

When Should You See a Doctor?

Consult your healthcare provider if you:

• Pass blood clots larger than approximately 2.5 cm.
• Experience heavy bleeding that soaks a pad or tampon every hour.
• Have periods lasting longer than seven days.
• Develop severe pelvic pain or worsening cramps.
• Feel dizzy, weak, or short of breath during your period.
• Notice bleeding between menstrual cycles.
• Pass blood clots during pregnancy.
• Experience vaginal bleeding after menopause.
• Have repeated heavy periods with large clots.
• Find that heavy bleeding significantly affects your daily activities or quality of life.

Early diagnosis can help identify treatable conditions and reduce complications such as anemia, chronic pelvic pain, and fertility problems.

Evidence: Clinical guidelines recommend investigating heavy menstrual bleeding associated with large clots through a detailed history, physical examination, laboratory testing, and imaging where appropriate. (Herman et al. 2016)

How Are Blood Clots During Periods Diagnosed?

Diagnosing the cause of menstrual blood clots focuses on determining whether the clots are part of a normal menstrual cycle or a sign of an underlying medical condition.

Your healthcare provider will perform a detailed assessment based on your symptoms, medical history, and menstrual pattern.

Medical History

Your doctor may ask about:

• The size and frequency of blood clots.
• The amount and duration of menstrual bleeding.
• The number of pads or tampons used each day.
• Whether bleeding interferes with daily activities.
• Pelvic pain or severe menstrual cramps.
• Bleeding between periods.
• Pregnancy history.
• Current medications, including blood thinners.
• Family history of bleeding disorders or uterine conditions.

Keeping a menstrual diary or using a period-tracking app can help identify patterns and assist with diagnosis.

Physical Examination

A physical examination may include:

• Blood pressure and pulse assessment.
• Abdominal examination.
• Pelvic examination.
• Assessment for signs of anemia, such as pale skin or rapid heart rate.
• Evaluation for uterine enlargement or pelvic tenderness.

Laboratory Tests

Depending on your symptoms, your healthcare provider may recommend:

• Pregnancy test
• Complete blood count (CBC)
• Iron studies (including ferritin)
• Thyroid function tests
• Coagulation profile
• von Willebrand disease testing (when indicated)
• Hormonal profile (FSH, LH, estrogen, progesterone)
• Infection screening if clinically suspected

Imaging Studies

Imaging helps identify structural abnormalities that may contribute to heavy bleeding and clot formation.

Common investigations include:

• Pelvic ultrasound
• Transvaginal ultrasound
• Saline infusion sonography
• MRI of the pelvis (selected cases)
• Hysteroscopy for direct visualization of the uterine cavity

Additional Investigations

Some women may require:

• Endometrial biopsy to evaluate abnormal uterine bleeding.
• Pap smear, if due for cervical screening.
• Referral to a hematologist when a bleeding disorder is suspected.

Prompt diagnosis helps ensure timely treatment and reduces the risk of complications such as anemia and reduced quality of life.

Evidence: Evaluation of heavy menstrual bleeding includes pregnancy testing, blood tests, pelvic imaging, and additional investigations based on the patient’s symptoms and clinical findings. (American Academy of Family Physicians (AAFP))

Treatment Options for Blood Clots During Periods

Treatment depends on the underlying cause, the severity of bleeding, your age, overall health, and whether you wish to become pregnant in the future.

Lifestyle Changes

Simple lifestyle measures can support overall menstrual and reproductive health.

These include:

• Eating an iron-rich, balanced diet.
• Maintaining a healthy body weight.
• Staying physically active.
• Drinking adequate fluids.
• Managing stress effectively.
• Getting sufficient sleep.
• Avoiding smoking and limiting alcohol consumption.

Medications

Your doctor may prescribe medications such as:

• Nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce pain and menstrual bleeding.
• Tranexamic acid to reduce heavy menstrual bleeding.
• Hormonal contraceptives.
• Oral progesterone therapy.
• Levonorgestrel-releasing intrauterine device (LNG-IUD).

Always take medications only as prescribed by your healthcare provider.

Treating the Underlying Condition

Management depends on the diagnosis.

Examples include:

• Fibroid treatment.
• Hormonal therapy for adenomyosis or endometriosis.
• Removal of uterine polyps.
• Treatment of thyroid disorders.
• Management of bleeding disorders.
• Pregnancy-related care when appropriate.

Surgical Treatment

Some women with persistent heavy bleeding may require procedures such as:

• Hysteroscopic polypectomy
• Myomectomy
• Endometrial ablation (for selected women who do not desire future pregnancy)
• Hysterectomy in carefully selected cases when other treatments have failed

Can Physiotherapy Help?

Women’s health physiotherapy cannot eliminate menstrual blood clots directly,

but it plays an important role in helping women manage symptoms associated with conditions that cause heavy menstrual bleeding.

Pelvic Floor Rehabilitation

Women experiencing pelvic pain, pelvic floor muscle dysfunction, or chronic pelvic conditions may benefit from:

• Pelvic floor muscle assessment.
• Relaxation exercises.
• Muscle coordination training.
• Manual therapy when appropriate.

Pain Management

Physiotherapy may help reduce discomfort through:

• Heat therapy.
• Gentle stretching.
• Manual therapy.
• Relaxation techniques.
• Breathing exercises.
• Postural education.

Therapeutic Exercise

Individualized exercise programs may include:

• Walking or low-impact aerobic exercise.
• Core strengthening.
• Pelvic stability exercises.
• Hip mobility exercises.
• Flexibility training.

Exercise should always be adjusted according to the severity of symptoms and medical advice.

Education and Self-Management

Education empowers women to:

• Recognize abnormal menstrual symptoms.
• Track menstrual bleeding patterns.
• Maintain healthy lifestyle habits.
• Seek timely medical evaluation when necessary.

Lifestyle and Self-Care Tips

These healthy habits may help support menstrual health and reduce the impact of heavy bleeding.

• Eat iron-rich foods such as spinach, beans, lentils, and lean meats.
• Include period foods rich in vitamin C to improve iron absorption.
• Stay well hydrated.
• Maintain a healthy body weight.
• Exercise regularly according to your comfort level.
• Manage stress through yoga, meditation, or breathing exercises.
• Track your menstrual cycle each month.
• Attend regular gynecological check-ups.
• Seek medical advice if bleeding patterns change significantly.

Can Blood Clots During Periods Be Prevented?

Not all causes of menstrual blood clots can be prevented.

However, maintaining overall reproductive health may reduce your risk of complications.

Helpful measures include:

• Treat hormonal disorders promptly.
• Follow treatment plans for fibroids or endometriosis.
• Maintain a healthy lifestyle.
• Avoid delaying medical evaluation for persistent heavy bleeding.
• Monitor changes in your menstrual cycle over time.

Lesser-Known Facts About Blood Clots During Periods

Many women are unaware that:

• Small menstrual blood clots are a normal part of heavy menstrual flow.
• The first one or two days of menstruation are when clots are most commonly seen.
• Large, frequent clots may indicate fibroids, adenomyosis, or bleeding disorders.
• Heavy menstrual bleeding is a leading cause of iron-deficiency anemia in women of reproductive age.
• Hormonal contraceptives often reduce both menstrual bleeding and blood clot formation.
• Keeping a menstrual diary can help healthcare providers identify abnormal bleeding patterns more accurately.

Expert Tips from a Women’s Health Physiotherapist

• Track both the amount of menstrual bleeding and the size of any blood clots.
• Don’t ignore heavy bleeding that affects your daily routine.
• Prioritize iron-rich nutrition if your periods are heavy.
• Stay physically active while modifying exercise intensity based on your symptoms.
• Seek early medical advice for persistent heavy bleeding or severe pelvic pain.
• Use heat therapy and relaxation techniques to help manage menstrual cramps.
• Remember that treatment is directed at the underlying cause rather than the blood clots themselves.

Conclusion

Blood clots during periods are often a normal part of menstruation, particularly during the heaviest days of bleeding.

Small clots generally occur because menstrual blood leaves the uterus more quickly than the body’s natural anticoagulants can prevent clot formation.

However, large, frequent, or painful blood clots, especially when accompanied by heavy menstrual bleeding, prolonged periods, severe pelvic pain, or symptoms of anemia,

may indicate an underlying medical condition such as uterine fibroids, adenomyosis, endometriosis, or a bleeding disorder.

Early medical evaluation allows appropriate diagnosis and treatment, helping to improve menstrual health and quality of life.

From a physiotherapy perspective,

symptom management through pain relief strategies, pelvic floor rehabilitation, therapeutic exercise, and patient education complements medical care and supports long-term pelvic and reproductive health.

Evidence: Evidence supports a multidisciplinary approach to managing heavy menstrual bleeding, combining medical treatment with lifestyle measures to improve symptoms, quality of life, and overall reproductive health. (Dixon et al. 2025)

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Medical Disclaimer!

This article has been reviewed and written under the guidance of our Head Physiotherapist, Dr. Kruti Raj (PT, MUHS,CPT,CMPT). The information shared is intended for educational purposes only and should not be considered a substitute for personalized medical advice, diagnosis, or treatment.

Please consult us or any other qualified healthcare professional before beginning any exercise program, especially if you are experiencing pain, recovering from injury, or managing a medical condition.