Irregular periods, or amenorrhea, are menstrual periods that aren't "regular." You may miss a period, have periods that are shorter or longer than normal, or heavier or lighter. There may be additional problems, too, that aren't due to pregnancy, breastfeeding, or menopause.
Many people experience irregular periods during their lifetime for a variety of reasons.
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Doctors define irregular periods as changes to a person’s normal menstrual cycles or periods.
Irregularities may include:
Irregular periods are also known as amenorrhea — the absence of normal periods.
The menstrual cycle is the series of hormonal changes that occur in the body to prepare for a possible pregnancy. Most people start their period between the ages of 11 and 15, and most menstrual cycles occur every 21 to 35 days.
Menstrual irregularities — irregular periods — are often a symptom of another condition.
There are two classifications of amenorrhea:
Ovulation can still occur during an irregular cycle, so you can still become pregnant even if you're having irregular periods. It's important to take birth control measures if you're having sex but don’t want to become pregnant.
About 14% to 25% of menstruating people will experience irregular periods. But amenorrhea that isn't linked to pregnancy, breastfeeding, or menopause occurs in only 5% of menstruating people.
Period irregularities may fall into a series of categories:
Period irregularities can be a natural part of life for menstruating people as a result of hormone changes, pregnancy, breastfeeding, or menopause.
But they can also indicate another health problem, such as:
Your menstrual cycle is the result of hormonal changes in your body produced by the hypothalamus and pituitary glands in the brain, the ovaries, and the uterus. Disruptions to the menstrual cycle can arise at every level.
When the hypothalamus fails to release the hormone GnRH (gonadotropin-releasing hormone) in a normal manner, it can cause hypothalamic amenorrhea. This may be due to a low body weight, increased stress levels, or strenuous exercise.
In a normal menstrual cycle, the release of GnRH by the hypothalamus will trigger the pituitary gland to release the hormones FSH (follicle-stimulating hormone) and LH (luteinizing hormone). Problems with other hormones located in the pituitary gland, such as TSH (thyroid-stimulating hormone) and prolactin, can cause menstrual irregularities, too.
You may be at an increased risk of an irregular period if you:
If you're pregnant and had menstrual irregularities before you conceived, you may be at a higher risk of developing preeclampsia during your pregnancy or having a low-birth-weight baby.
Because irregular periods may cause a disruption to/lack of ovulation, some people may have a more difficult time getting pregnant. Consult with your doctor and a fertility specialist if you have period irregularities and are trying to get pregnant.
The main symptom of period irregularities is a missed period.
Irregular periods may also cause:
A regular menstrual cycle is a function of your overall health. If you miss a period for reasons other than pregnancy, breastfeeding, or menopause, you should talk to your doctor. It may be the result of another health problem.
To diagnose menstrual irregularities, your women's health provider will first evaluate your medical history and perform a physical exam.
Your doctor will want to know:
If you're over 16 and have never had your period, your doctor may also conduct a pelvic exam to look for signs of puberty.
It's helpful to keep track of your periods and share this tracking with your doctor. You should record when a cycle starts, how long it lasts, and any problems that you experience during the cycle. The first day of menstrual bleeding marks the first day of your cycle.
Your doctor may also order tests to figure out why your periods are irregular.
If you're sexually active, your doctor will most likely ask you to take a pregnancy test.
Other tests for irregular periods may include:
Sometimes, no specific cause for period irregularities may be found. This is called idiopathic amenorrhea.
Treatment for your irregular periods will depend largely on why they're irregular. The goal of treatment will be to correct the underlying condition.
For example, if you have primary amenorrhea, your doctor may recommend waiting to see if your period begins. It's common for people with primary amenorrhea — especially those with a family history — to have delayed periods due to low hormone levels.
But if your primary amenorrhea is due to a chromosomal or genetic problem, or you have a physical condition like an imperforate hymen, your doctor may recommend surgery.
You may be prescribed hormone therapy to help to regulate your cycle. For instance, if you have secondary amenorrhea, birth control pills or other medication can regulate your hormones.
Or, you may be prescribed medication to alleviate symptoms of PCOS, or for estrogen replacement therapy (ERT) if your body isn't producing a normal level of estrogen during your menstrual cycle.
A medication called Provera may be prescribed for a short time to try to induce a period. This can also help your doctor evaluate whether your ovaries are producing estrogen in a normal manner.
If your doctor suspects that your period irregularities are the result of lifestyle factors, they may recommend that you:
Occasionally, surgery may be recommended for treating secondary amenorrhea.
This may include:
Last reviewed by a UPMC medical professional on 2024-09-05.
