• Heavy menstrual bleeding, called menorrhagia, is fairly common but may lead to serious complications.
  • Untreated heavy menstrual bleeding can cause anemia.
  • If you experience weakness, dizziness, shortness of breath, or chest pain along with heavy menstrual bleeding, it’s recommended that you seek medical attention.

You likely have a go-to self-care routine when it comes to your period. Maybe you stock up on supplies, chocolate, and pain medication and get that heating pad ready to toss in the microwave.

How do you know if your bleeding is normal or not?

According to the Women’s Health Concern, the patient arm of the British Menopause Society, 1 in 20 people who menstruate have menorrhagia.

The term “menorrhagia” means bleeding that’s very heavy. It’s also defined as having a period that lasts more than 7 days or involves passing large blood clots.

Menstrual flow will vary from person to person. You might be used to it, but heavy bleeding could be a sign of a more serious condition. In some cases, medical attention is needed.

Keeping reading to learn more about some of the causes of heavy menstrual bleeding and symptoms to watch for.

It can take a serious toll on your body when a significant amount of blood is lost every month. Don’t hesitate to seek emergency care if you experience new or severe symptoms related to heavy menstrual bleeding.

Uterine lining is rich in iron, so you lose iron every time you have your period. Heavy periods can be linked to anemia. Anemia occurs when your body doesn’t have enough of certain blood cells or when blood cells aren’t functioning properly.

Anemia can make you feel:

  • weak
  • tired
  • lightheaded

Anemia can also cause:

  • shortness of breath
  • chest pain

Those symptoms might also have other causes, so it’s recommended that you seek medical attention if you experience them.

In very rare cases, there’s so much blood loss that it affects how your body functions. When body fluids get too low, it’s called hypovolemia. This can lead to:

  • increased heart rate
  • low blood pressure
  • dizziness
  • feeling faint

Hypovolemia is an emergency that requires immediate medical attention.

The official definition of menorrhagia is based on the amount of bleeding and how long it lasts.

During an average period, 2 to 3 tablespoons of blood is lost over 4 or 5 days. It’s considered heavy bleeding if you lose more than this amount of blood during your period and/or if you bleed for at least 7 days.

If you have any of the following signs or symptoms, it’s worth talking with a doctor:

  • You pass clots the size of a quarter or larger.
  • You get up during the night to change your pad or tampon.
  • During the day, you have to change your pad or tampon at least every hour for several hours in a row.
  • You use a reusable menstrual cup and bleed 5 milliliters or more an hour for several hours in a row.
  • You bleed so much that having your period keeps you stuck at home.
  • You have significant abdominal pain and cramping that interferes with your regular routine.
  • You don’t meet those above criteria, but the bleeding is affecting your well-being.

There are several possible causes of heavy menstrual bleeding. Your doctor will ask more about your symptoms and medical history. Bloodwork or medical imaging may be done to further investigate.

Here are some reasons why your bleeding may be so heavy.

  • Uterine fibroids. Uterine fibroids are benign (not cancerous) tumors that grow in the walls of the uterus. Heavy bleeding is one of the most common symptoms. They can also cause lower back pain and pressure.
  • Uterine polyps. Also called endometrial polyps, these benign growths may cause bleeding inside the uterus.
  • Bleeding disorders. Low platelet count is a common cause of heavy bleeding. Normally, platelets stick together to clot blood and slow bleeding. The most common bleeding disorder is called von Willebrand disease.
  • Polycystic ovary syndrome (PCOS). People with PCOS have an imbalance in hormones, which can cause irregular periods and/or heavier bleeding. Other symptoms include facial hair growth, acne, and weight gain. It’s one of the major causes of infertility.
  • Thyroid disease. When your thyroid hormones are in balance, they keep a variety of body systems working properly. In some cases, thyroid hormone levels are too low (hypothyroidism) or high (hyperthyroidism). Either condition can make your period irregular or cause heavier bleeding.

Heavy menstrual bleeding can have major effects on your health and well-being. It’s important to pay attention to your body and seek help if you need it.

Low iron levels

Red blood cells carry oxygen around the body. When you don’t have enough iron, you can’t make enough red blood cells and iron deficiency anemia can occur.

Symptoms include:

  • feeling fatigued
  • weak
  • lightheaded

In some cases, there are not enough red blood cells to bring oxygen around the body. This can cause:

  • chest pain
  • shortness of breath

Sleep disruption

It’s hard to get enough sleep when your flow is so heavy that you’re waking multiple times overnight. Lack of sleep can affect your mood and energy levels.


For many people, heavy bleeding during periods is associated with abdominal pain. This combination can make it especially hard to function.

Depending on the cause of heavy bleeding, there are a variety of treatment options.

  • Fibroid treatment. If uterine fibroids are found in or around your uterus, there are several procedures available to treat them. Uterine fibroid embolization, for example, shrinks fibroids by blocking their blood supply. Fibroids can also be surgically removed.
  • Hormonal birth control. Birth control pills can be helpful if a hormonal imbalance is the reason for heavy bleeding. Many people find that their periods are lighter on hormonal birth control.
  • Treatment for bleeding disorder. You may be given medications or transfusions to increase the platelets in your blood.
  • Treatment for thyroid disease. High thyroid levels may be treated with medications or surgery. Low thyroid levels are treated with synthetic thyroid hormone pills.
  • Dilation and curettage procedure (D and C). To help reduce menstrual bleeding, the top layer of the lining of the uterus is removed. This reduces menstrual flow. This procedure isn’t permanent and will likely need to be repeated.
  • Restore iron levels. Depending on your iron levels, supplements or an iron transfusion can help. Normalizing iron levels can help improve your energy levels and prevent or treat anemia.

Untreated heavy bleeding can lead to iron deficiency anemia. If you’re experiencing dizziness, weakness, shortness of breath, or chest pain along with heavy menstrual bleeding, seek medical attention.

According to research, 1 in 20 people who menstruate have heavy menstrual bleeding. Some common causes include uterine fibroids or hormonal imbalances.

The first step in managing heavy bleeding is to figure out the cause. Once that’s determined, there may be medications and treatments available to help.

Talk with your doctor to create a treatment plan that’s right for you.