Missed Period in 40s: Perimenopause or Another Cause?

Posted by AweSamo February 20, 2026
Missed Period: Is It Perimenopause or Something Else?

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.

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