Heavy Period Flow: What Causes Heavy Bleeding During Period?

Heavy period flow (also called heavy menstrual bleeding or menorrhagia) is when your menstrual bleeding is much heavier or lasts longer than usual and starts to affect your daily life.

If you are pregnant, think you could be pregnant, or have heavy bleeding after childbirth or miscarriage, you should seek urgent medical care – this article is mainly about heavy periods in non-pregnant women. Heavy menstrual bleeding is common and can often be treated. 

Are you worried about the length of your period? Do you feel your period contains a lot of clots? Are you worried about the amount of bleeding during your period?

This article will explain what a heavy period means, the causes and how to get rid of it.

---

What is Normal period length and menstrual flow?

In women, period occurs due to regular cyclic shedding of the endometrium covering the uterus. This is due to hormonal changes that occur during the menstrual cycle.

What is menstrual cycle? Menstrual cycle is the time difference between 2 of your periods. It varies from women to women but usually last 21 to 35 days.

How long do your period last? Normal girls period last for 2 to 7 days. Period flow may be heavy during the first days of menstruation. However as your period progresses, it becomes lighter with less pain during period.

How does period occur? During your cycle, estrogen and progesterone play a crucial role to ensure the thickening and maturation of the endometrium. After ovulation occurs and if the egg released is fertilized by the sperm, it is implanted into the endometrium.

Before ovulation, estrogen is the dominant type of hormone produced by the growing follicles. However, after ovulation, the ruptured follicle forms the corpus luteum which increases production of progesterone.

If your egg released is not fertilized and implanted into the uterus, it causes the corpus luteum to breakdown. This will result to decreased hormones and shedding of your endometrium as period.

When is period said to be prolonged?

Long or prolonged periods is when your menstruation last more than the usual 7 days.

---

What is very heavy period flow or menses?

Normal blood loss during period in women is usually less than 80mls (about 5–6 tablespoons) in one cycle. If your period is more than 80mls or the bleeding is so heavy that it affects your daily life, then it is considered heavy menstrual bleeding.

However, it may be difficult to calculate how much of blood you’ve lost during menstruation. One easy way to know is the frequency at which you change you pads. If you change pads too frequently than usual it could mean heavy or increased menstrual flow. Doctors also become concerned if you are soaking a pad or tampon every 1–2 hours, passing large clots, or developing symptoms of anemia such as tiredness and shortness of breath.

Heavy period symptoms are

• Changing your pads every 1 or 2 hours during the days

• Waking up many times at night to change your pads

• Trying to double your pads to prevent staining

• Feeling weak after days of very heavy bleeding

• Extremely heavy periods affecting your daily activities or work

If you have any of these symptoms, then your period may be heavy. To understand how much blood you lose during periods, you should monitor your period length and menstrual cycle.

• Record the number of sanitary pads you change day and night. Is it fully soaked with period blood clots?

• Record the length of your menstrual cycle. Is your menstrual cycle getting shorter or longer? Learn how to calculate your menstrual cycle.

• Try to remember the last time you had a normal period flow. If this is the first time, then stressful activities could play a role.

When should you see a doctor urgently?

See a doctor or go to the emergency room urgently if:

• You are soaking through a pad or tampon every hour for several hours.

• You feel dizzy, faint, short of breath, or your heart is racing.

• You pass very large clots (for example, larger than a golf ball).

• You have heavy bleeding after sex, after menopause, after a recent delivery or miscarriage, or if you might be pregnant.

You can read more about abnormal bleeding and when to worry in the ACOG information on abnormal uterine bleeding.

---

What causes heavy period flow in women?

If your period is heavy with very frequent change of pads in few hours or your periods are now lasting longer than usual, then these are the possible causes.

Fibroid

Fibroid are benign mass or growth that affects the uterus. They are non-cancerous, but can cause very heavy bleeding and sometimes fertility problems, depending on their size and where they are located in the uterus. Uterine fibroid can be found on the surface of the uterus or within the uterine muscle.

The risk to having fibroid are

• Women over 30 years, especially in their 30s and 40s

• You’ve never been pregnant before. If you’ve had several full-term pregnancies, then it is less likely you may have a fibroid.

• You are obese or overweight

• A female family member, either your mother or sister, had a fibroid

• You are African or black skinned

What causes fibroid in women? Its still unclear what really causes women to have fibroid. However, estrogen reduction after menopause seems to reduce the size of uterine fibroid. It is therefore believed that estrogen and other hormones in younger women play a role in the growth of the tumor.

So what are fibroid symptoms?

Symptoms of fibroid depends on the size of the tumor and where in the uterus it is located.

The most common type of fibroid that causes bleeding is submucous fibroid (a fibroid that grows into the cavity of the womb).

Symptoms of fibroid are

• Sometimes extremely heavy periods

• Distended abdomen if tumor is very huge

• Spotting in between periods

• Spotting before periods

• Obstructive symptoms like difficult in passing urine and stool

• Infertility

---

Pelvic inflammatory disease (PID)

Pelvic inflammatory disease, commonly called PID, is the spread of vaginal infections to the upper parts of the genital tracts of women like the uterus and fallopian tubes. It is usually due to gonorrhea or chlamydia vaginal infections. However, other vaginal infections like bacterial vaginosis can sometimes be present at the same time.

If you’ve had intercourse without condom then its possible you could have PID. Symptoms of PID are

• Fever

• Lower abdominal pain

• Abnormal discharge that is smelly

• Difficulty in getting pregnant

• Prolonged or irregular periods and bleeding after sex

If you develop these symptoms, then it may be the cause of your heavy bleeding during periods.

What to do if i have PID?

Inform your doctor to prevent complications like ectopic pregnancy or conception problems. During your clinic visit, your vaginal discharge and blood will be tested. If the cause of your heavy bleeding during periods is due to PID, it will be treated with antibiotics, and your sexual partner(s) may also need treatment.

---

Endometrial polyp or uterine polyps

These are hanging mass attached to the uterine wall. They can sometimes protrude into the cervical canal and cause bleeding during intercourse. Symptoms of an endometrial polyps are

• Very heavy bleeding during periods

• Bleeding after menopause

• Bleeding in between periods

• Pain during periods

Uterine polyps are common in women taking hormone replacement with only estrogen, obese women and women with high blood pressure, and they are more often seen around perimenopause and menopause.

---

Bleeding disorders

Heavy periods may be due to coagulation or bleeding disorders. If you have an unexplained bleeding during periods, it may be suspected. Also, your previous history may help make a diagnosis.

• Did you bleed for days after previous childbirth or surgery?

• Do you have heavy bleeding from small cuts?

• Is there a family problem with wound healing or heavy bleeding?

If you’ve had these problems in the past or in your family, you should inform your doctor. In some girls and women, heavy periods are the first sign of an inherited bleeding problem. You can read more in this ACOG guidance on bleeding disorders and heavy menstrual bleeding.

---

Endometrial hyperplasia and cancer

Endometrial hyperplasia, which is the overgrowth and thickening of the endometrium, can cause heavy period flow.

It is due to unopposed effects of estrogen especially in women taking hormone replacement or diseases like polycystic ovarian syndrome. Symptoms are:

• Bleeding or spotting between period

• Sometimes extremely heavy periods

If your heavy period is due to cancer, then you may experience any of these symptoms

• Vaginal heavy bleeding

• Pain during sexual intercourse

• Weight loss

Both endometrial cancer and hyperplasia is usually common in women over the age of 40. Your chances to have cancer increases if you’re

• Obese

• Diabetic

• Never had a pregnancy before

• Having bleeding after menopause (any vaginal bleeding after 12 months without a period should be checked by a doctor)

---

Other causes of heavy period flow are

• Copper intrauterine contraceptive device (some non-hormonal IUDs)

• Thyroid disorders

• Drugs like warfarin and heparin can increase blood loss during period

• Adenomyosis

• Endometriosis

Sometimes, no clear cause is found even after tests. Doctors may call this “heavy menstrual bleeding with no structural cause”, but it can still be treated. You can read more about causes and treatment options in the NICE heavy menstrual bleeding guideline for patients and this overview from Patient.info.

---

Heavy period treatment in women

Heavy period is abnormal and you should inform your doctor. These are some ways you can get rid of heavy period:

How to get rid of heavy period medically

Mefenamic acid

This drug is a non-steroidal anti-inflammatory drug that reduces blood loss during period (and improves period pain) when taken regularly during menstruation. It is however not advised if you have a history of serious stomach ulcers, kidney disease, or allergy to NSAIDs. Always take it only as prescribed by your doctor.

Tranexamic Acid

This drug is used when you experience heavy periods and is usually taken only on the heavy days of your cycle. It can reduce excessive bleeding during period by around 25–50 percent in women. It is not a hormone. It may not be suitable for women with a history of blood clots or certain medical conditions, unless a specialist advises it.

Combined oral contraceptives pills

This has been very useful in treating heavy periods in women. It also helps as a contraceptive to prevent pregnancy. However, it is not suitable for some women, especially smokers over 35 years, women with uncontrolled high blood pressure, migraine with aura, or women at high risk of blood clots. Your doctor will check your risk factors. Weight changes can occur but are usually small.

Hormonal intrauterine system

Use of levonorgestrel IUDs reduces bleeding to a great extent (often up to about 90–95 percent over time) in women. Though it can cause breakthrough bleeding during the first months, it reduces blood loss and painful periods in many women and is recommended as a first-line option in several guidelines such as NICE.

Gonadotropin releasing hormone agonist (GnRH)

This drugs act on the pituitary to reduce or stop production of estrogen. Decreased estrogen will cause absent periods. However, these drugs are not used for long term. If used for more than 6 months, it causes hot-flushes, irregular periods, sweating and osteoporosis. They are usually used short-term to shrink fibroids or as a bridge while preparing for surgery.

How to get rid of heavy period surgically

Surgery can be an option if medically treatment of heavy flow fails. If you already completed childbirth, then surgery option totally solves your bleeding problems.

Endometrial ablation

This process uses heat, radiofrequency, freezing or an electrical diathermy loop to destroy the endometrium, preventing it from regenerating. It is usually offered only to women who have completed childbearing because pregnancy after ablation can be risky.

Hysterectomy (Removal of the uterus.)

Myomectomy (Removal of the fibroid mass.)

You can read more about treatment options and their pros and cons on Mayo Clinic’s treatment page for heavy menstrual bleeding and at the Cleveland Clinic menorrhagia page.

---

FAQs about heavy bleeding during periods?

These are some frequently asked questions that may concern you. If you have any other questions about heavy bleeding during period let us know by commenting below.

What causes heavy period with blood clots?

If you have heavy periods with small blood clots then it could be normal — Especially if it occurs in the first 1 or 2 days of your period. During early menstruation, excessive clots not broken down by fibrinolysin may come out as blood clots. Causes of heavy period with large clots are submucous fibroid, infection or endometrial thickening. Very large clots, or clots that continue for many days, should always be checked by your doctor.

I have extremely heavy period? Is it normal?

Extremely heavy period is abnormal. If you change multiple sanitary pads every hours, then its abnormal. Causes are fibroids, some types of birth control, bleeding disorders and (less commonly) cancer. Always inform your doctor if you have an extremely heavy period with blood clots.

What causes really heavy periods in women?

• Uterine fibroid

• Bleeding disorders in women

• Drugs like warfarin and heparin

• Pelvic inflammatory disease (PID)

• Cancer

• Endometrial hyperplasia

• Polycystic ovaries (polycystic ovary syndrome)

• Estrogen-only hormone replacement therapy

Any of these could cause a really heavy periods. Inform your doctor ASAP.

What causes heavy painful periods?

If you have heavy painful periods, then its likely due to

• Endometriosis — This is endometrial tissues found outside your uterus. It can cause painful and heavy periods. Analgesics like ibuprofen can subside the pain.

• Adenomyosis — This is presence of endometrial tissues inside the wall of the uterus. It can be treated with analgesics or cured with removal of the uterus.

• Uterine fibroid

• Pelvic inflammatory disease

What causes sudden heavy period with blood clots?

If you have a sudden heavy period, then these are the likely causes

• Miscarriage

• Stress

• Recent long travel

• Acute illness

• Pelvic inflammatory disease

• You are on a birth control pill

• You inserted an IUD

• Polycystic ovaries

• Vaginal infections

• Fibroid

If there is a chance you could be pregnant (for example, your period is late and the bleeding is sudden and heavy), you should do a pregnancy test and seek urgent medical help.

How many liters of blood do you lose during your period?

During women period, it is estimated that blood loss should be less than 80 milliliters (mls) in total. If your period exceeds 80mls during menstruation, then its abnormal. Most women lose much less than this.

Can heavy period cause fatigue or body weakness?

Yes. If your period is extremely heavy with blood clots for days it can cause fatigue and body weakness. This is due to anemia. Other symptoms of anemia if you have heavy period flow are:

• Difficulty in breathing

• Fast heart rate

• Dizziness

• Feeling faint

• Headaches

Why is my period so heavy this month?

If you have a heavy menstruation for the first time, then it may likely not be a problem. However, heavy persistent period is abnormal.

One of these may be the reason your period is heavier this month

• Vaginal infections

• Stress

• Pelvic inflammatory disease

• You started a birth control pill

• Polycystic ovaries

• Fibroid

If you have heavy menstruation this month, then you should monitor your next period. Is your heavy period persistent? Is it getting worse? Then its abnormal. You should inform your doctor.