Suffering from heavy bleeding during periods? Here are 10 causes of Heavy Periods.


It’s often difficult for women to recognise whether their bleeding is abnormal.

That’s because menstrual patterns vary significantly between women.

In this article, we’re going to talk about “what is a normal period?”, how to recognise excessive menstrual bleeding,  and the 10 causes of heavy menstruation.


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What is a normal period? 

For the average female, menstrual bleeding happens for 5 days.
However, some women’s periods last for as little as 2 days, or go as long as 7 days at a time.
While women menstruate once every 28 days on average, the timing between each period is your cycle length and can vary between 21 to 35 days.

What is an abnormally heavy period?

Your may have abnormally heavy periods, otherwise known as menorrhagia, if you:
  1. Bleed for longer than 1 week
  2. Need to change your pad or tampon very frequently during your period
  3. Pass large amounts of clots
  4. Feel that your lifestyle/activities are restricted due to your bleeding
  5. Have symptoms of anaemia – tiredness, weakness, giddiness, breathlessness, chest discomfort


Menorrhagia is not to be taken lightly! If you have these symptoms, seek help from a doctor.

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10 causes of heavy menstruation

Why is my period so heavy?


1. Hormonal imbalances

Menstruation occurs due to the complex interaction amongst several hormones within the female body. If these hormones are imbalanced, heavy bleeding can occur. Multiple factors impact hormone balance, including but not limited to: lifestyle, stress, illness and medication use.

2. Fibroids

Growths within the walls of your womb (uterus) are called fibroids. They occur commonly amongst pre-menopausal women, and can cause heavy or prolonged bleeding.

3. Polyps

Small areas of tissue growth from the surfaces of your womb (uterus) or cervix can be sensitive and prone to bleeding. This can take the form of heavy bleeding during the period, in between periods (inter-menstrual bleeding), or bleeding after sex.

4. Endometriosis

The endometrium is the lining of the womb that develops during each menstrual cycle, and is shed during the period. Abnormal, excessive growth of endometrial tissue can result in heavy bleeding, and painful periods.

5. Cancer

Whilst rare, heavy menstrual bleeding can sometimes be a sign of cancer of the cervix, uterus, endometrium, or ovaries.

6. Pregnancy-related

An ectopic pregnancy occurs when the fertilised egg implants in an area outside the uterus, usually along the Fallopian tube. Ectopic pregnancies, along with miscarriages, are pregnancy related complications that can cause a delayed period and heavy menstrual bleeding.

7. Bleeding disorders

Disorders of the blood clotting system are conditions usually inherited, and carried within families. Ask your family members about a history of abnormal bleeding, if you are experiencing heavy periods.

8. Medications 

Certain medications that are taken to treat conditions like heart disease, stroke, or previous blood clots can all result in thinning of the blood, thereby contributing to heavy bleeding.

9. Sexually Transmitted Diseases (STDs)

STDs can lead to a more serious condition known as pelvic inflammatory disease (PID), which is associated with heavy bleeding. Other symptoms of STDs or PID include bleeding after sex, abnormal vaginal discharge, vaginal itching, lower abdominal pain, and pain during sex.

Click to find out more about STDs,  bleeding after sex, and vaginal discharge.

10. Other medical conditions

Kidney, liver or thyroid disease can also interfere with your menstruation and cause excessive menstrual bleeding.

 If you’re experiencing heavy bleeding, don’t ignore it. 

Prolonged heavy bleeding can eventually lead to a low blood count, which can be dangerous.

Consult a doctor to find out more about investigations and treatment.

Need a Female Doctor?

Having Women’s Health concerns? Please visit us or contact us at our GP Plus Clinics in Singapore. We are open on weekends too. For more information, visit DTAP Clinic website, or email them at


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