Generally, a period lasts between three to seven days. A menstrual period that lasts longer than seven days is considered a long period.

Your doctor may refer to a period that lasts longer than a week as menorrhagia. You may also be diagnosed with menorrhagia if you experience unusually heavy bleeding that lasts less than a week. Five percent of women have menorrhagia.

A long period may be a sign of a serious underlying health condition, such as:

  • hormone irregularities
  • uterine abnormalities
  • cancer

It’s important to see your doctor if you experience a long or heavy period so they can identify the underlying cause or rule out more serious possible causes.

Menorrhagia can cause discomfort during your period as well as disrupt your regular routine. You may find that the bleeding affects your activities or your sleep. You may also experience iron deficiency anemia if you regularly experience long menstrual periods, especially if they’re heavy.

Read on to learn more about long periods, including possible causes and what you can do to manage this symptom.

Long periods can be caused by a wide range of underlying conditions.

Hormone and ovulation changes

Changes to your hormones or ovulation may cause a long period. You may notice hormonal changes when you first get your period during puberty or in perimenopause. You may also experience a hormonal imbalance from different health conditions, such as thyroid disorders or polycystic ovary syndrome.

If your hormones aren’t at a normal level or if your body doesn’t ovulate during your menstrual cycle, the uterine lining can become very thick. When your body finally sheds the lining, you may experience a period that’s longer than normal.

Medications

You may experience long periods because of medications you take. These can include:

  • contraceptives, such as intrauterine devices and extended birth control pills
  • aspirin and other blood thinners
  • anti-inflammatories

Pregnancy

While not actually a period, extended vaginal bleeding may be a sign of an unsafe or nonviable pregnancy, such as an ectopic pregnancy or a miscarriage.

You may also have extended bleeding in pregnancy if you have a condition like placenta previa.

If you’ve had a pregnancy test come back positive and you’re experiencing vaginal bleeding, see your healthcare provider.

Uterine fibroids or polyps

Uterine fibroids and polyps can lead to extended, and sometimes heavy, bleeding.

Fibroids occur when muscle tissue begins to grown in the wall of the uterus.

Polyps are also the result of irregular tissue growth in the uterus and cause small tumors to grow.

Generally, neither fibroids or polyps are cancerous.

Adenomyosis

Adenomyosis is another type of tissue buildup. The condition occurs when your endometrium, or uterine lining, embeds itself into the muscles of your uterus. This can lead to a long or heavy period.

Thyroid condition

You may have a long period if your thyroid is underperforming. This condition is known as hypothyroidism.

Bleeding condition

You may have a condition that affects your body’s ability to clot blood, causing your long periods. Two of these conditions are hemophilia and von Willebrand’s disease.

A long period may be the only sign of one of these conditions, or you may have other symptoms.

Obesity

Excess weight may cause long periods. That’s because fatty tissue can cause your body to produce more estrogen. This excess estrogen can lead to a change in your period.

Pelvic inflammatory disease

Pelvic inflammatory disease (PID) occurs when bacteria infect your reproductive organs. In addition to changes to your menstrual cycle, PID can also lead to abnormal vaginal discharge among other symptoms.

Cancer

A prolonged period may the sign of cancer in your uterus or cervix. For some women, this may be one of the earliest symptoms of either of these cancers.

Don’t ignore a long period. It’s important to see your doctor to discuss why you might be experiencing this symptom. Delaying your diagnosis and treatment could lead to a worsening of the underlying condition responsible for the extended bleeding.

You may want to seek immediate care with a long period if you spike a fever or are losing an abnormally heavy amount of blood or large blood clots. A sign that you’re losing a lot of blood is if you need to change a pad or tampon one to two times per hour for several hours. You may also begin to feel lightheaded if you’re losing a lot of blood.

There are many causes for a long period, so your doctor will likely begin your appointment by asking you some questions. These may include:

  • when your period started
  • how many pads and tampons you’ve used in the last day
  • your sexual activity
  • other symptoms you’re experiencing
  • your medical and relevant family histories

They may also do a physical exam that includes a pelvic exam and measuring your vital signs.

Your doctor may also recommend any of the following tests to help them make a diagnosis:

Treatment methods for a long period can vary. Your doctor will treat the underlying cause. They may also recommend a treatment to reduce your current bleeding, regulate your period, or relieve any discomfort.

Hormonal birth control may regulate your period and shorten it in the future. This medication can be administered as:

  • a pill
  • an intrauterine device
  • a shot
  • a vaginal ring

Your doctor also may advise you to take medication that reduces pain or discomfort you experience from the prolonged period. These medications may include over-the-counter nonsteroidal anti-inflammatories, such as Advil or Motrin.

In some cases, your doctor may recommend a surgical procedure to alleviate long periods.

Dilation and curettage can thin the layer of your uterus and reduce how much you bleed during your period.

If you’re no longer considering having children, you may undergo endometrial ablation, resection, or a hysterectomy. These procedures can relieve the long periods, but they may also eliminate the possibility of getting pregnant.

Delaying a diagnosis could result in a more invasive procedure or intensive treatment for the underlying cause.

Additionally, if your long period causes heavier blood loss, you could be at risk of developing anemia. This may contribute to feelings of tiredness and weakness.

Your doctor can use results from a blood test to diagnose anemia. If your iron levels are low, your doctor may recommend boosting your diet with iron-rich foods and a possible iron supplement to get your levels back to normal.

Long periods may also be painful and interfere with your well-being and quality of life. You may miss days of school or work, or withdraw from activities you enjoy because of your long period.

There are many reasons you may have a period that’s longer than normal. Long periods can get in the way of your normal life, and they may also be a sign of an underlying condition that requires treatment.

See your doctor to find out the cause of your long period so you can begin to treat it. Delaying treatment may cause complications and lead to more invasive treatments in the future.