Your menstrual cycle is counted from the first day of your last period to the start of your next period. Your period is considered irregular if it's longer than 38 days or if the duration varies.
Irregular periods can have several causes, from hormonal imbalances to other underlying conditions, and should be evaluated by your doctor. Here's a look at the possible causes and their symptoms.
If you miss a period or notice changes in your period and you've had sex, you can take a pregnancy test at home or see your doctor to find out if you're pregnant.
Birth control pills may cause spotting between periods and result in much lighter periods.
An IUD may cause heavy bleeding.
Prolactin is a hormone that's responsible for breast milk production. Prolactin suppresses your reproductive hormones resulting in very light periods or no period at all while you're breastfeeding.
Your periods should return shortly after you stop breastfeeding. Read on to learn more the effects of breastfeeding on your period.
You may experience signs and symptoms lasting from 4 to 8 years, beginning with changes to your menstrual cycle. Fluctuating estrogen levels during this time can cause your menstrual cycles to get longer or shorter.
Other signs and symptoms of perimenopause include:
Irregular periods are the most common sign of PCOS. If you have PCOS, you may miss periods and have heavy bleeding when you do get your period.
PCOS can also cause:
A 2015 study found that 44 percent of participants with menstrual irregularities also had thyroid disorders.
Hypothyroidism, or underactive thyroid, can cause longer, heavier periods and increased cramping. You may also experience fatigue, sensitivity to cold, and weight gain.
High levels of thyroid hormones, which is seen in hyperthyroidism, can cause shorter, lighter periods. You may also experience:
Swelling at the base of your neck is another common sign of a thyroid disorder.
- pelvic pain or pressure
- low back pain
- pain in your legs
- pain during sex
Most fibroids don't require treatment and symptoms can be managed with over-the-counter (OTC) pain medications and an iron supplement if you develop anemia.
Endometriosis causes very painful, even debilitating menstrual cramps. Endometriosis also causes heavy bleeding, prolonged periods, and bleeding between periods.
Other symptoms may include:
- gastrointestinal pain
- painful bowel movements
- pain during and after intercourse
Exploratory surgery is the only way to diagnose endometriosis. There's currently no cure for the condition, but symptoms can be managed with medication or hormone therapy.
Rapid weight gain can also cause menstrual irregularities. Weight gain and irregular periods are common signs of PCOS and hypothyroidism, and should be evaluated by your doctor.
See your doctor if:
- you're underweight
- have lost a lot of weight without trying
- you have an eating disorder
Intense or excessive exercise has been shown to interfere with the hormones responsible for menstruation.
Female athletes and women who participate in intensive training and physical activities, such as ballet dancers, often develop amenorrhea, which is missed or stopped periods.
Cutting back on your training and increasing your calorie count can help restore your periods.
Research shows that stress can interfere with your menstrual cycle by temporarily interfering with the part of the brain that controls the hormones that regulate your cycle. Your periods should return to normal after your stress decreases. Try these 16 techniques to relieve your stress.
Certain medications can interfere with your menstrual cycle, including:
- hormone replacement therapy
- blood thinners
- thyroid medications
- epilepsy drugs
- chemotherapy drugs
- aspirin and ibuprofen
Speak to your doctor about changing your medication.
Cervical and endometrial cancers can cause changes to your menstrual cycle, along with bleeding between periods or heavy periods. Bleeding during or after intercourse and unusual discharge are other signs and symptoms of these cancers.
Remember that these symptoms are more commonly caused by other issues. Speak to your doctor if you're concerned.
There are several possible causes of irregular periods, many of which require medical treatment. Make an appointment to see your doctor if:
- your periods stop for more than 3 months and you're not pregnant
- your periods become irregular suddenly
- you have a period that lasts longer than 7 days
- you need more than one pad or tampon every hour or two
- you develop severe pain during your period
- your periods are less than 21 days or more than 35 days apart
- you experience spotting between periods
- you experience other symptoms, such as unusual discharge or fever
Your doctor will ask about your medical history and want to know about:
- any stress or emotional issues you're experiencing
- any changes to your weight
- your sexual history
- how much you exercise
Medical tests may also be used to help diagnose the cause of your irregular bleeding, including:
Treatment depends on what's causing your irregular periods and may require treating an underlying medical condition. Your doctor may recommend one or more of the following treatments:
- oral contraceptives
- hormonal IUDs
- thyroid medication
- weight loss or weight gain
- vitamin D supplements
Stress reduction techniques may also help, including:
- deep breathing
- cutting back on work and other demands
Tracking your period is a good idea even when your period is regular. You can track your period on a calendar or in a notebook, or use one of the many period tracking apps available.
Begin tracking your period by marking the first day of your period on a calendar. Within a few months you'll begin to see if your periods are regular or different each month.
Keep track of the following:
- PMS symptoms, such as headaches, cramps, bloating, breast tenderness, and moods
- when your bleeding begins and whether or not it was earlier or later than expected
- how heavy your bleeding was, including how many pads or tampons you used
- symptoms during your period, such as cramping, back pain, and other symptoms and how bad they were
- how long your period lasted and whether or not it was longer or shorter than your last period