Missed Period in 40s: Perimenopause or Another Cause?

Missed Period: Is It Perimenopause or Something Else?

Missed Period: Is It Perimenopause or Something Else?
Adobe Stock

Checking the calendar and realizing your period hasn’t shown up this month can bring up a lot of questions. If your cycle is usually predictable and you’re in your forties, you may be wondering what your body is trying to tell you, and if this means you’re in perimenopause (the transitional phase leading up to menopause).

While perimenopause is a common reason for missed periods at this stage of life, it’s not the only possibility.

 Aside from pregnancy, your cycle can be affected by stress, changes in your weight, or underlying health conditions.

Here are the most common reasons for a missed period in your forties and how to tell whether it might be perimenopause or something else entirely.

Is It Perimenopause? The Early Warning Signs

The most common sign of perimenopause is unpredictable menstrual cycles, says Rhiana Saunders, MD, a reproductive endocrinologist and infertility specialist at Aspire Houston Fertility Institute in Texas. “Normally, as women approach menopause, they may notice their cycles change to shorter intervals, from every 28 to 30 days to 23 to 25 days,” she says.

These shorter cycles can last for a long time and happen because the follicular phase (the first part of the menstrual cycle before you ovulate) is shrinking, explains Anupama Rambhatla, MD, a board-certified obstetrician-gynecologist and reproductive endocrinology and infertility specialist in Newport Beach, California. Cycles can also become longer.

If a cycle is 35 days long, that could seem like a missed period.
Eventually, as the ovaries no longer respond predictably to the hormones your brain releases, your menstrual cycles can become even more irregular, and your periods begin to skip months at a time.

Changes in the menstrual flow are also common during perimenopause. Some women notice much heavier periods than they’re used to, which can lead to fatigue or symptoms of anemia (low red blood cell levels), says Dr. Saunders.

Beyond changes to your cycle, perimenopause often brings other telltale signs, such as:

  • Stronger premenstrual symptoms (PMS), like breast tenderness, bloating, mood swings, and irritability
  • Hot flashes or night sweats, which happen when lower estrogen levels affect how the brain regulates body temperature
  • Trouble falling or staying asleep
  • Vaginal dryness

But everyone experiences perimenopause differently. Some people find their symptoms minor and manageable, and for others, their quality of life is significantly affected.

Is It Something Else? Common Reasons For a Missed Period

A missed period doesn’t always mean perimenopause, even if you’re in your forties. Several reasons that have nothing to do with approaching menopause can affect your menstrual cycle in this stage of life, says Eric Liberman, DO, a board-certified obstetrician-gynecologist based in Teaneck, New Jersey. Some reasons for a missed period include the following.

Pregnancy

It may seem obvious, but pregnancy is still one of the most common reasons for a missed period in your forties.

 Even if your cycles have already started changing, it’s still important to check for pregnancy first, if it’s a possibility. “Pregnancy is easily diagnosed with a pregnancy test,” Dr. Liberman says.

Hormonal Imbalances

“The endocrine system is a fine-tuned communication system that allows certain organs to communicate with each other using hormones as chemical messengers,” says Liberman. An imbalance in any hormone, even one not directly related to reproduction, can create a ripple effect that disrupts your menstrual cycle.

Thyroid conditions are a common example, says Liberman. The thyroid helps regulate metabolism and energy use, but thyroid hormones also play a role in reproductive function. When thyroid levels are too low (hypothyroidism) or too high (hyperthyroidism), your period may become irregular or stop altogether.

Polycystic ovary syndrome (PCOS) is another hormonal condition that can affect your cycle, Liberman says. Women with PCOS often have higher-than-normal testosterone levels, which can prevent ovulation (the release of an egg).

 Without ovulation, the menstrual cycle doesn’t happen regularly, leading to skipped or widely spaced periods.
You may also experience missed periods if your prolactin levels are too high.

 Prolactin is the hormone that helps the body produce breast milk after pregnancy, but levels can rise even when someone isn’t pregnant or breastfeeding.

Certain medications, stress, or problems with the pituitary gland can increase prolactin and interfere with ovulation, leading to missed periods.

Weight Changes

Fat cells contain an enzyme that converts certain hormones into estrogen.

 When someone carries extra body fat, and they’re not in menopause or perimenopause, they may produce more estrogen, says Liberman. “These increased levels of estrogen trick the body into thinking you are pregnant and prevent the release of an egg,” he says, and without the release of an egg, your body doesn’t produce enough progesterone, which is needed to trigger a period.

This hormone pattern can sometimes lead to heavier bleeding later on because the lining of the uterus continues to thicken from the continuous estrogen instead of shedding on a regular schedule, says Liberman.

Saunders says that conditions related to being underweight or having low body fat, whether from intense athletic training, like marathon running, eating disorders, or not eating enough calories, can affect ovulation as well.

 Many women experience missed or irregular periods when their body mass index (BMI) drops below 18.5, she says.

In these cases, the brain tries to conserve energy and doesn’t release the hormones that allow for ovulation and menstruation.

Stress

If you’re wondering how stress can affect your period, it has to do with cortisol, the main stress hormone. Ongoing stress raises cortisol levels, which can interfere with the hormones that regulate ovulation and menstruation.

 During stressful times in life, your cycle may become irregular or pause until your cortisol levels are better regulated.

Finding ways to manage stress, such as with exercise, therapy, meditation, or other relaxation techniques, may help your cycle return to its usual pattern.

Certain Medications

Consider looking at your medicine cabinet if your menstrual cycles have changed. Some medications can affect cycle timing and bleeding patterns, says Dr. Rambhatla, including hormonal birth control, certain antidepressants and antipsychotic drugs, and high-dose steroids.

If your periods started changing after you began a new medication, speak with the healthcare professional who prescribed it to see whether the medication could be playing a role.


Other Medical Conditions

Sometimes, a missed period can be a sign of an underlying health issue.

 While these aren’t the most common causes, they’re worth being aware of:
  • Hormone-Producing Tumors Certain rare ovarian tumors, like granulosa cell tumors, can produce estrogen on their own, which can interfere with your normal cycle.

  • Asherman’s Syndrome Scar tissue that forms inside the uterus after certain procedures can physically block menstrual flow, making it seem like periods have stopped.

  • Chronic Illnesses Poorly controlled diabetes, autoimmune diseases, or other long-term health conditions, can put enough strain on your body to disrupt the hormones that regulate your cycle.

  • Uterine or Ovarian Conditions Ovarian cysts, fibroids, or polyps can change your bleeding patterns, often making periods unpredictable.

Many of these causes are treatable, which is why ongoing missed periods should be checked out by a healthcare provider.

How to Tell the Difference

When missed periods occur alongside symptoms like hot flashes, night sweats, poor sleep, or mood changes, perimenopause is often the more likely explanation, says Rachel Pope, MD, a board-certified obstetrician-gynecologist based in Ohio and associate professor of obstetrics and Gynecology at Case Western Reserve University School of Medicine.

While medical conditions like PCOS or thyroid disorders can affect your cycles, Dr. Pope says they usually come with different patterns or clues.

Use the table below to compare perimenopause with other common causes of missed periods in your forties:

Possible Cause
Other Symptoms and Common Clues
What to Do
Perimenopause
Hot flashes, night sweats, sleep changes, mood shifts, vaginal dryness
Track symptoms and cycle dates. Talk to a healthcare provider if symptoms affect your quality of life.
Pregnancy
Nausea, breast tenderness, fatigue, frequent urination
If pregnancy is possible, take a pregnancy test.
Thyroid problems
Weight changes, heat or cold intolerance, hair and skin changes, heart palpitations, constipation, diarrhea, fatigue

Discuss symptoms and thyroid testing with your healthcare provider.

PCOS
Acne, facial and body hair growth, scalp hair thinning, weight gain
Discuss symptoms and PCOS evaluation with your healthcare provider.
High prolactin levels
Milky nipple discharge, headaches, vision changes (rare)
Discuss symptoms and review the medications you take with your healthcare provider.
Stress
Sleep problems, anxiety, fatigue, changes in appetite
Use stress management techniques. A healthcare provider can help look into other possible causes.
Weight changes
Weakness, dizziness, feeling cold, low energy (for weight loss); or a gradual increase in body fat (for weight gain)

Focus on adequate nutrition and healthy eating patterns. Discuss symptoms and healthy weight management with your healthcare provider.

Seeing a Doctor

Any change in your menstrual pattern is a good reason to see your gynecologist, says Earl Peeper, MD, a board-certified obstetrician-gynecologist based in New Orleans.

“In our forties, periods can become very unpredictable, and keeping track of what is happening through a journal or an app can help a woman pick up new patterns,” says Pope. Having this information ready can make it easier to discuss management and treatment options with your gynecologist.

Seek medical care right away if you notice missed periods that alternate with random, heavy bleeding, such as passing clots, soaking through pads or tampons, or if your cycles are becoming unusually close together, says Liberman. This is especially important if you have certain risk factors, including:

  • Obesity
  • PCOS
  • High blood pressure
  • Diabetes
  • Family history of certain cancers (uterine, colon, ovarian, or breast)
  • Prior use of tamoxifen (a hormone-blocking medication used in breast cancer treatment)
  • Inherited gene mutation, such as Lynch syndrome or BRCA

If you’ve already reached menopause — meaning you’ve gone a full 12 months without a period — discuss any new spotting or bleeding, even if it’s light, with your gynecologist, Liberman says.

On the flip side, if you’re in your mid-to-late fifties or older and still having regular vaginal bleeding without ever going a full year without a period, that’s also worth mentioning to your provider.

 Conditions like polyps in the uterus or fibroids can cause ongoing bleeding and may be delaying your transition to menopause.

The Takeaway

  • A missed period in your forties could be perimenopause, especially if you’re also experiencing hot flashes, night sweats, sleep problems, or mood changes.
  • Missed periods can also occur due to pregnancy, stress, weight changes, medications, hormonal conditions like thyroid disease or PCOS, or other medical issues.
  • See a gynecologist if you miss more than three periods, have heavy or unusual bleeding, or notice other concerning symptoms, such as passing clots or bleeding between periods.

Resources We Trust

EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
  1. Perimenopause. Cleveland Clinic. August 8, 2024.
  2. Eisenberg E. My Periods Have Changed. Is Menopause Around the Corner? American College of Obstetrics and Gynecologists. February 2024.
  3. The Menopause Years. American College of Obstetrics and Gynecologists. December 2025.
  4. Am I Pregnant? Cleveland Clinic. July 26, 2022.
  5. The Menstrual Cycle. UCSF Health.
  6. Thyroid Disease. Office on Women’s Health. December 6, 2024.
  7. Polycystic Ovary Syndrome (PCOS). Cleveland Clinic. February 15, 2023.
  8. Prolactin. Cleveland Clinic. December 30, 2024.
  9. Hyperprolactinemia. Cleveland Clinic. December 24, 2024.
  10. Hetemäki N et al. Adipose Tissue Estrogen Production and Metabolism in Premenopausal Women. The Journal of Steroid Biochemistry and Molecular Biology. February 24, 2021.
  11. Endometrial Hyperplasia. Cleveland Clinic. February 16, 2023.
  12. Amenorrhea: Absence of Periods. American College of Obstetrics and Gynecologists. May 2024.
  13. Boegl M et al. The LH:FSH Ratio in Functional Hypothalamic Amenorrhea: An Observational Study. Journal of Clinical Medicine. February 19, 2024.
  14. How Stress Can Impact Your Menstrual Cycle. Cleveland Clinic. September 24, 2025.
  15. Ramanathan B et al. Fluoxetine Brakes the Menstrual Cycle: Uncovering the Unexpected Effect. Industrial Psychiatry Journal. February 6, 2024.
  16. Irregular Periods. Cleveland Clinic. January 18, 2023.
  17. Amenorrhea. Cleveland Clinic. March 23, 2023.
  18. Granulosa Cell Tumor. Cleveland Clinic. October 3, 2022.
  19. Amenorrhea. Mayo Clinic. February 9, 2023.
  20. Oligomenorrhea. Cleveland Clinic. April 25, 2022.
  21. Uterine Fibroids. Office on Women’s Health. February 28, 2025.
  22. Perimenopausal Bleeding and Bleeding After Menopause. American College of Obstetricians & Gynecologists. February 2024.
kara-leigh-smythe-bio

Kara Smythe, MD

Medical Reviewer

Kara Smythe, MD, has been working in sexual and reproductive health for over 10 years. Dr. Smythe is a board-certified fellow of the American College of Obstetricians and Gynecologists, and her interests include improving maternal health, ensuring access to contraception, and promoting sexual health.

She graduated magna cum laude from Florida International University with a bachelor's degree in biology and earned her medical degree from St. George’s University in Grenada. She completed her residency in obstetrics and gynecology at the SUNY Downstate Medical Center in Brooklyn, New York. She worked in Maine for six years, where she had the privilege of caring for an underserved population.

Smythe is also passionate about the ways that public health policies shape individual health outcomes. She has a master’s degree in population health from University College London and recently completed a social science research methods master's degree at Cardiff University. She is currently working on her PhD in medical sociology. Her research examines people's experiences of accessing, using, and discontinuing long-acting reversible contraception.

When she’s not working, Smythe enjoys dancing, photography, and spending time with her family and her cat, Finnegan.

Maggie-Aime-bio

Maggie Aime, MSN, RN

Author

Maggie Aime is a registered nurse with over 25 years of healthcare experience, who brings medical topics to life through informative and inspiring content. Her extensive nursing background spans specialties like oncology, cardiology, and pediatrics. She has also worked in case management, revenue management, medical coding, and as a utilization review nurse consultant. She leverages her unique insights to help individuals navigate the U.S. healthcare system and avoid financial pitfalls.

Maggie applies her extensive clinical expertise to create empowering education for readers at all stages. She is passionate about illuminating issues from disease prevention to health and wellness to medical personal finance. Her work can be found in GoodRx Health, Next Avenue, HealthNews, Insider, Nursing CE Central, Nurse Blake, AllNurses, and BioHackers Lab.

An active member of several professional nursing and journalism associations, Maggie founded The Write RN to fulfill her calling to teach.

When she's not crafting the next great article, you can find Maggie volunteering, reading, playing the piano, or savoring sunrise views at the beach.