An Overview of Oligomenorrhea

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Oligomenorrhea is infrequent or unusually light bleeding during your menstrual periods. Specifically, it refers to a menstrual cycle that lasts longer than 35 days or when you have fewer than nine periods in a year.

There are several causes of oligomenorrhea, some of which are harmless. In fact, light menstrual periods may be totally normal for you. However, in some instances, oligomenorrhea can be a sign of a more serious health condition.

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Missing a period or occasional irregularity of the menstrual cycle is not uncommon and is not necessarily a sign that something is wrong. Some variation in a person’s menstrual cycle throughout their life is normal.

The hormones that influence the menstrual cycle can be temporarily influenced by a number of different factors. However, if a person’s periods suddenly become different and do not return to what has been normal for most of their menstrual life, it’s important to figure out what’s caused the change.

The symptoms of oligomenorrhea include:

  • Going longer than 35 days without a period
  • Having fewer than nine periods in a year
  • Menstrual cycles that are irregular
  • Periods that are lighter than usual

When the different bleeding happens, you may have other symptoms of your period, such as premenstrual syndrome, cramps, and bloating. You may have no other symptoms at all.

The blood may be dark brown, red, or a faint light pink color. You may notice clots or mucus when you wipe, on a pad or tampon, or in your underwear.


In a regular menstrual cycle, hormonal changes signal the lining of the uterus to build up each month in preparation for a fertilized egg. Of course, an egg does not always find its way to the uterus. When the lining is not needed, the tissue sloughs off, passes through the cervix and into the vagina, where it can then leave the body in the form of a period.

This process happens every month or so, though the normal variation in menstrual cycle length can be slightly longer or shorter than 28 days.

It's more important to pay attention to is what is "normal" for you and make note of any major change.

For example, you might typically get a period every 30 days. Then, they start coming less frequently: every 35, 40, or more days. They may also be lighter than usual.

Unless a person is controlling their cycle with hormonal birth control, their normal menstrual cycle may vary in length from month to month.

Menarche and Perimenopause

When a young person first begins having menstrual cycles, it can take several years for periods to establish a regular pattern. In the beginning, erratic bleeding and periods that are heavier or lighter than the previous month’s are not unusual. As time goes on, hormones usually stabilize.

Changes in the menstrual cycle can also happen when a person is entering menopause. The hormonal changes taking place to facilitate this transition often lead to periods that come sooner or later than expected, varying in duration and heaviness, until they finally stop altogether.

Life Changes

Menstrual cycles may also change in response to other changes in a person’s life. For example, getting pregnant, giving birth, and breastfeeding a baby can all affect a person’s periods.

Changes to your lifestyle, such as going on vacation, having stress at work, or losing a lot of weight, can also affect your period. Being malnourished can cause your periods to become erratic and they may even stop (amenorrhea). People with eating disorders such as anorexia nervosa who become severely underweight often stop having a menstrual cycle.

Intense Exercise

People who exercise or train intensely for a sport can also experience changes to their menstrual cycle. Some elite athletes have very light periods or no period at all due to the intensity of their training.

Being Overweight

On the other end, being overweight or obese can also affect your cycle. Estrogen, a key hormone for regulating menstruation, is found in body fat. Having more body fat increases your estrogen levels, which can impact the menstrual cycle.

Weight-related causes of menstrual cycle irregularities can usually be addressed by maintaining a healthy weight.

Certain Medications

Certain medications, especially hormonal birth control, can majorly change a person’s menstrual cycle. Taking birth control pills or getting shots like Depo-Provera, using a patch or ring, or having an IUD inserted can lead to period changes.

In some people, periods may become more frequent and heavier, but you may also experience the light, infrequent periods that define oligomenorrhea.

If you use birth control irregularly or change methods frequently, it can cause abnormal or unpredictable bleeding.

This will usually get better when you start consistently using a form of birth control that works well for you.

While it can cause unwanted changes and side effects, hormonal birth control is often used to treat problems with the menstrual cycle. Some people who menstruate may choose to use continuous forms of hormonal birth control to reduce the duration or frequency of their periods or suppress them altogether.

Other medications that can impact the menstrual cycle include:

  • Anticoagulants like aspirin
  • Epilepsy treatments
  • Anti-anxiety or antipsychotic medications

Underlying Health Conditions

Oligomenorrhea can be a sign of several underlying health conditions, including:

  • Primary ovarian insufficiency
  • Pelvic inflammatory disease
  • Polycystic ovarian syndrome (PCOS)
  • Hyperprolactinemia (elevated levels of prolactin in the blood)
  • Prolactinomas (adenomas on the anterior pituitary gland)
  • Hormone-secreting tumors
  • Thyroid disorders
  • Obstructions of the uterus, cervix, and/or vagina
  • Anabolic steroid use
  • Graves’ Disease
  • Prader-Willi syndrome
  • Uncontrolled Type 1 and Type 2 diabetes


When you visit your healthcare provider with concerns about your menstrual cycle, they will start by asking you questions about your health. They may also ask you about the menstrual health of your mother, aunts, or sisters, and if they have ever been diagnosed with a reproductive health condition or cancer.

You will need to see a specialist in reproductive health, called an obstetrician/gynecologist (OBGYN). They will ask you more in-depth questions and may do an exam.

An OBGYN will talk to about your symptoms and may ask you questions about your sexual history as well as any pregnancies and births you’ve had. You may be asked about other health conditions or surgeries you’ve had, as well as any medications and supplements you take.

Tell your healthcare provider as many specific details about the bleeding as you can, including how long it lasts and how heavy it is. They can use this information to figure out what's causing it.

Your healthcare provider may do a rectovaginal exam, which can help them feel for any abnormalities they can't see on an exam. Using a lubricated, gloved, finger they will gently feel inside your rectum and vagina. You may experience some brief discomfort or feel embarrassed, but the exam will be over quickly.

You may also need to have a vaginal exam using a speculum. This helps your OBGYN see inside your vagina, up to your cervix. They may use a swab that looks like a long Q-tip to take a sample which can be tested for infection.

If at any point during these exams you are in pain or feel uncomfortable (physically or emotionally) tell your healthcare provider or the nurse right away. You can ask to pause and take a break or stop the exam altogether at any time.


If your healthcare provider isn't sure what is causing the change in your periods they might want to order some other types of tests. The first tests they try will usually be less invasive and gradually become more involved if they feel a more thorough investigation is needed.

To start, you may need to provide a blood or urine sample. These can be tested for a number of conditions that can cause menstrual irregularities.

Tests your healthcare provider may order to diagnose the cause of oligomenorrhea include:

  • Blood tests to check for disorders that cause bleeding, nutritional deficiencies, infections, markers of inflammation, and other findings
  • Tests to check your hormone levels and thyroid function
  • Urine samples to check for pregnancy, infection, or STDs
  • Pap smear to test for cervical cancer
  • Other tissue biopsies to look for other types of cancer

Your healthcare provider may also use imaging tests to look at your reproductive organs, including:

  • Ultrasounds of your abdomen and pelvis, including transvaginal ultrasounds
  • CT scans or MRIs


If none of these tests reveal a cause, your healthcare provider might want to do surgery. They may also refer you to a surgeon who specializes in reproductive health.

In most cases, the first type of surgery they will try is a minimally-invasive procedure called a laparoscopy. This surgery only requires a few tiny incisions in your belly to allow the surgeon to use a camera and some tools to explore your abdominal and pelvic cavity. The procedure usually has a shorter recovery time than other types of surgery and can be very useful in diagnosing conditions that don't show up on a blood test or ultrasound, such as endometriosis.

In some cases, you may need a more involved type of surgery called a laparotomy. This procedure requires bigger or more incisions and has a longer recovery period. It's possible that if you are scheduled to have a laparoscopy, you may end up needing a laparotomy to deal with what the surgeon finds. Your healthcare provider will go over this information, as well as the risks and benefits of each procedure, before your surgery. Be sure to ask them any questions you have and share your concerns.


Once your healthcare provider figures out what is causing you to have oligomenorrhea, they will discuss treatment options with you.

Which treatment is right for you will depend on the cause as well as your overall health. Some types of treatments may not be right for you even if they work well for other people.

For example, while hormonal birth control can be used in many people to treat menstrual problems, if you have a history of blood clots, it may not be safe for you to use.

Lifestyle Changes

If oligomenorrhea is related to something in your lifestyle, such as your weight, exercise routine, or stress levels, your healthcare provider can help you get the resources and support you need to make changes. You may find that the problems with your period get better on their own after you return from a vacation, start a new work schedule, or gain weight if you are underweight.

Birth Control or Hormone Therapy

If you have certain conditions that respond to hormones, your healthcare provider might ask you about trying different types of birth control to manage your periods. You can use these medications even if you are not sexually active or have never had sex.

There are many different options, including pills, patches, rings, and IUDs. Your healthcare provider can help you decide which one is right for you. You may need to try more than one method to find one that helps your symptoms. With hormonal birth control, you also need to give your body time to adjust to a method before deciding it doesn't work—this may mean several months.

Another type of hormone therapy your healthcare provider may prescribe is gonadotropin-releasing hormone (GnRH) agonists. However, you should know that these medications are not meant to be used long-term and also have side effects. Your healthcare provider will help you decide if the risks outweigh the benefits.

Treating Underlying Health Conditions

If you are diagnosed with a sexually transmitted infection, you may be given antibiotics to treat it. It's important that you tell any sexual partners you've had about your diagnosis so they can be tested and treated as well. While you are being treated, you'll want to abstain from having sex of any kind to prevent the spread of the infection. When you resume having sex, be sure that you consistently practice safe sexual practices.

If you are experiencing oligomenorrhea as a result of another health condition, you may need to see a different type of healthcare provider to ensure it is treated. Different healthcare providers specialize in treating different parts of the body. Depending on the underlying disease or condition you have, a healthcare provider (or team of healthcare providers) can help you manage it.

For example, if you are diagnosed with a thyroid condition, an endocrinologist can help you find the right medication for treating it. Once your condition is being managed, you will likely notice symptoms such as oligomenorrhea begin to resolve.

While it's less common, you may also be diagnosed with a more serious condition. Benign and cancerous tumors of the reproductive system can cause oligomenorrhea and often need to be treated with specialized surgery.

If you are diagnosed with cancer, you may need to have other treatments as well, including radiation and chemotherapy. In some cases, your healthcare providers may recommend that you have your ovaries, fallopian tubes, uterus, and/or cervix removed (partial or complete hysterectomy). If your ovaries and uterus are completely removed, you will no longer have a menstrual cycle.

A Word From Verywell

Oligomenorrhea is having infrequent or abnormally light periods. It is usually defined as having a menstrual cycle that goes on longer than 35 days or having fewer than nine periods in an entire year. Some variation in the menstrual cycle is a normal part of changing hormones throughout life, especially when a person first starts having periods, after they have a baby, and when they are approaching menopause.

There are several causes of oligomenorrhea, including health conditions, medications, and lifestyle factors like weight and stress. Some of these causes are only temporary and may resolve on their own. However, other more serious causes, including several types of reproductive cancer, need early diagnosis and treatment.

The treatment for oligomenorrhea will depend on what's causing it as well as a person's individual state of health, preferences, and needs. Your healthcare provider will help you make an informed decision about treating any menstrual irregularities you experience.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Rebar R. Evaluation of amenorrhea, anovulation, and abnormal bleeding. In: Feingold KR, Anawalt B, Boyce A, et al., editors. Endotext. South Dartmouth (MA):, Inc.

  2. The American College of Obstetricians and Gynecologists. Abnormal Uterine Bleeding.

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Additional Reading

By Abby Norman
Abby Norman is a freelance science writer and medical editor. She is also the author of "Ask Me About My Uterus: A Quest to Make Doctors Believe in Women's Pain."