Irregular Periods

Menstrual periods typically last four to seven days and occur roughly every 28 days. Examples of irregular periods include periods that occur fewer than 21 days or more than 35 days apart, missing three or more periods in row, and menstrual flow that’s much heavier or lighter than usual.


What are irregular periods?

Most women and people assigned female at birth (AFAB) have menstrual periods that last four to seven days. Your period usually occurs every 28 days, but normal menstrual cycles can range from 21 days to 35 days. In fact, the average cycle length is 29 days. Many things cause irregular periods (or irregular menstruation) such as changes in hormone levels, stress, certain health conditions, medications and more.


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What are examples of irregular periods?

Your period is still considered “regular” even if it varies slightly from cycle to cycle. Examples of irregular menstruation include:

  • Periods that occur fewer than 21 days or more than 35 days apart.
  • Missing three or more periods in a row.
  • Menstrual flow (bleeding) that’s much heavier or lighter than usual.
  • Periods that last longer than seven days.
  • Length of time between cycles varies by more than nine days. For example, one cycle is 28 days, the next is 37 days and the next is 29 days.
  • Periods that are accompanied by severe pain, cramping, nausea or vomiting.
  • Bleeding or spotting that happens between periods, after menopause or after sexual intercourse.
  • Soaking through one or more tampons or sanitary pads in an hour.

Your menstrual cycle may not always be predictable — and that may be OK. It’s normal to have slight variations in cycle length or have a menstrual period that seems slightly heavier or lighter in flow than your previous period. Menstrual irregularities are fairly common, and you don’t have to be able to predict your cycle to the exact day for it to be considered “normal.”

Conditions related to irregular menstruation

  • Amenorrhea: A condition where your periods have stopped completely. The absence of a period for 90 days or more is considered abnormal unless you’re pregnant, breastfeeding or going through menopause (which generally occurs between ages 45 and 55). If you haven’t started menstruating by age 15 or 16 or within three years of your breasts developing, you may also have amenorrhea.
  • Oligomenorrhea: A condition where your periods occur infrequently. You may go more than 35 days between periods or have six to eight periods a year.
  • Dysmenorrhea: A medical term for painful periods and severe menstrual cramps. Some discomfort during your cycle is normal.
  • Abnormal uterine bleeding: Abnormal uterine bleeding is bleeding between monthly periods, prolonged bleeding or an extremely heavy period.

Symptoms and Causes

What is the cause of my irregular periods?

There are many causes of irregular periods, ranging from stress to more serious underlying medical conditions.

Medical conditions and irregular periods

Certain health conditions are associated with missed menstrual periods. They include:

  • Endometriosis: Endometriosis occurs when endometrial tissue grows outside of your uterus. The tissue often attaches itself to your ovaries or fallopian tubes. Endometriosis may cause abnormal bleeding, cramps or severe pain before and during your period.
  • Pelvic inflammatory disease: Pelvic inflammatory disease (PID) is a bacterial infection that affects the female reproductive system. It’s typically caused by an untreated sexually transmitted infection (STI). Bacteria enter your vagina and spread to your uterus and upper genital tract. Symptoms of PID include a heavy vaginal discharge with an unpleasant odor, irregular periods and pelvic pain.
  • Polycystic ovary syndrome: In polycystic ovary syndrome (PCOS), your ovaries make large amounts of androgens, which are a type of hormone. This hormone prevents or delays ovulation, causing irregular periods. People with PCOS may stop menstruating completely.
  • Primary ovarian insufficiency: This condition occurs in cisgender women under age 40 whose ovaries don’t function as they should, causing missed or irregular periods. It can occur during treatment for cancer with chemotherapy and radiation or if you have certain autoimmune conditions.
  • Thyroid or pituitary gland disorders: Hypothyroidism (underactive thyroid), hyperthyroidism (overactive thyroid) and other thyroid or pituitary gland disorders affect your hormones. This causes your period to be irregular.
  • Bleeding disorders: You may experience heavy menstrual bleeding if you develop a bleeding or blood clotting disorder.
  • Uterine cancer or ovarian cancer: Certain cancers can affect a person’s menstrual period. Changes may include bleeding that’s heavier than usual or missed periods.

Lifestyle factors and irregular periods

Disruptions or changes in your daily routine can have an impact on your menstrual cycle. Some examples of lifestyle factors include:

  • Stress.
  • Gaining or losing a significant amount of weight.
  • Exercise routines that result in very low body fat (long-distance runners, dancers or gymnasts).
  • Viruses or other illnesses.

Other causes of abnormal menstruation

Certain medications, complications of pregnancy or breastfeeding (chestfeeding) may also cause your period to be irregular. Other causes include:

  • Birth control pills: Most birth control pills contain a combination of hormones. The pills prevent pregnancy by keeping your ovaries from releasing eggs. Going on or off birth control pills can affect menstruation. You may have irregular or missed periods for up to six months after discontinuing birth control pills.
  • Medications, such as steroids or anticoagulant drugs (blood thinners).
  • Miscarriage or an ectopic pregnancy (the fertilized egg implants outside your uterus).
  • Surgery, scarring or blockages in your uterus, ovaries or fallopian tubes.


Diagnosis and Tests

How are irregular periods diagnosed?

If you sense changes in your menstrual cycle, begin keeping records of when your periods begin and end. Note symptoms, the amount of flow or if you experience cramping, bleeding between periods or passing large clots. These are all helpful to share with your healthcare provider.

To diagnose irregular periods, your provider will ask you about your menstrual cycle and medical history. They’ll perform a physical examination, including a pelvic exam. They might also order certain tests, including:

  • Pelvic ultrasound: An ultrasound can detect irregular bleeding due to uterine fibroids, polyps or an ovarian cyst.
  • Endometrial biopsy: Your provider removes a sample of tissue from the lining of your uterus. It can help diagnose endometriosis, hormonal imbalances or precancerous cells.
  • Hysteroscopy: A procedure that allows your provider to look inside your uterus in order to diagnose and treat certain causes of abnormal bleeding.

Management and Treatment

How are irregular periods treated?

The treatment for irregular periods depends on the underlying cause.

Medication for irregular periods

Medications are often the first treatment for irregular periods. If medication doesn’t help, your provider may recommend surgery. Possible medications include:

  • Hormonal birth control: Irregular or heavy bleeding caused by PCOS, uterine fibroids, endometriosis or other medical conditions may be managed with hormonal birth control. They also help by regulating your cycle, making it more predictable. These can be combination hormonal birth control pills that consist of estrogen and progestin, or progestin-only birth control. Both types come in different forms like pills, a vaginal ring, injection or an IUD (intrauterine device).
  • Tranexamic acid:A medication prescribed to treat heavy menstrual bleeding. You take one pill at the start of your period to control your bleeding.
  • Pain relievers: You may find relief from mild to moderate pain or cramps by taking an over-the-counter pain reliever, such as ibuprofen or acetaminophen.
  • Hormone therapy:Hormone therapy may be helpful if your irregular period is due to perimenopause. It can also help with other menopausal symptoms like vaginal dryness and hot flashes. There are risks associated with hormone therapy, so be sure to discuss these with your healthcare provider.
  • Antibiotics:You may be given antibiotics if the cause of irregular bleeding is from an infection.
  • Gonadotropin-releasing hormone agonists:These medications shrink the size of uterine fibroids and control heavy bleeding, but temporarily stop your menstrual period.

Surgery for irregular periods

There are surgical treatment options depending on your condition, age and whether you want to get pregnant in the future. Surgical treatments for irregular periods include:

  • Endometrial ablation: Endometrial ablation is a procedure that uses heat, cold or different types of energy to destroy the tissue that lines your uterus so you bleed less during your period. You must have a form of birth control to have this procedure. If you still wish to get pregnant in the future, you shouldn’t have this procedure.
  • Myomectomy: A procedure to remove uterine fibroids, a cause of irregular bleeding.
  • Uterine artery embolization: A procedure that cuts off blood supply to your uterus in order to stop uterine fibroids.
  • Hysterectomy: In severe cases, surgery may be necessary to remove excess endometrial tissue growing in your pelvis or abdomen. A hysterectomy might be required as a last resort if your uterus has been severely damaged.



How can I lower my risk of having an irregular period?

Here are some recommendations for self-care:

  • Try to maintain a healthy lifestyle by exercising moderately and eating nutritious foods. If you want to lose weight, do it gradually instead of turning to diets that drastically limit your calorie and food intake.
  • Make sure you get enough rest.
  • Practice stress reduction and relaxation techniques.
  • Cut back on prolonged or intense exercise routines.
  • Use birth control pills or other contraceptive methods as directed.
  • Change your tampons or sanitary pads every four to six hours to avoid toxic shock syndrome and prevent infections.
  • See your gynecologist and primary care provider for regular check-ups.

Living With

When should you see your provider about irregular periods?

Contact a healthcare provider if you have painful or irregular periods or any of the following symptoms:

  • Severe pain (cramping) during your period or between periods.
  • Unusually heavy bleeding (soaking through a sanitary pad or tampon every hour for two to three hours) or passing large clots (larger than a quarter).
  • Foul-smelling vaginal discharge.
  • A period lasting longer than seven days.
  • Vaginal bleeding or spotting between periods or after you’ve gone through menopause.
  • Periods that become very irregular after you’ve had regular menstrual cycles.
  • Nausea or vomiting during your period.
  • Symptoms of toxic shock syndrome (TSS), such as fever, vomiting, diarrhea, fainting or dizziness.

You should also see your provider if you think you might be pregnant.

Additional Common Questions

Is it normal to miss a period for two months?

Skipping one or two periods isn’t ideal, but it’s not too concerning. Take a look at any changes in your life recently. Things like stress, a new workout routine, losing or gaining weight, or changing birth control can all impact your cycle. Call your healthcare provider if you miss your period for three or more months in a row or if you experience other unusual symptoms during your next period.

How much delay in periods is normal?

Slight delays in your period are typically OK. Some people are able to predict their period to the exact day, while others can’t. Contact your provider if you notice a sudden change in the time between cycles or the duration (days) of your period, especially if it’s significant. This doesn’t always indicate a problem, but it’s a good idea to get it checked out.

When are irregular periods more common?

Irregular periods are more common when you first begin menstruating (around age 9 to 14) or during perimenopause (around age 50 or just before menopause).

Should I be worried if my period is irregular?

Irregular periods may be nothing to worry about because some variation in menstruation is normal. What’s normal for you may be different from what’s normal for your closest friends. However, certain symptoms could be a sign of a bigger problem.

Contact your gynecologist if you’re concerned about your menstrual cycle or if you’re trying to get pregnant and have unpredictable periods (this can make getting pregnant difficult). They’ll be able to tell you what’s normal and if treatment is needed.

A note from Cleveland Clinic

There are many causes for irregular periods and menstrual irregularities. Contact your healthcare provider if you experience drastic changes in your menstrual cycle or your period becomes extremely painful. Most causes of irregular periods aren’t serious and are treatable with medication by your healthcare provider. Keep in mind that slight variations between cycles or in the duration of your period usually aren’t a cause for worry. Everyone’s “normal” is different. If you sense something is off with your menstrual period, write down what’s changed and your symptoms so you can talk to your provider.

Medically Reviewed

Last reviewed on 01/18/2023.

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