Skip to main content

We’ve updated our Terms & Conditions and Privacy Policy. By using this site, you agree to these terms.

All Geisinger locations are open and providing patient care. Please arrive as scheduled for your appointment unless you hear from a member of your care team. We appreciate your patience if you experience any delays during your visit.

Your period can have a mind of its own.

Abnormal or irregular bleeding isn’t always cause for concern. Occasional changes happen. But when your cycle changes altogether, it can be frustrating. From hormonal imbalances to too much stress, here are some possible reasons for your unpredictable flow.

What are irregular periods?

“A typical menstrual cycle lasts between 21 and 35 days,” says Pam Gressens, CRNP, a nurse practitioner at Geisinger Saint Luke’s Women’s Health in Orwigsburg. If your cycle falls outside this window, it may be irregular.

Other symptoms of an irregular period can include:

  • Heavier or lighter than normal periods
  • Painful periods
  • Menstrual cycle longer than 38 days or shorter than 24
  • Bleeding or spotting between periods

Causes of irregular periods

Your menstrual cycle can change over time. And many things can lead to abnormal bleeding, including:


You may notice spotting or light bleeding in the early stages of pregnancy. That bleeding typically happens when an embryo implants in your uterus. Bleeding during early pregnancy can signify hormonal shifts, cervical changes or miscarriage.

Birth control

Contraceptives can cause a type of spotting called breakthrough bleeding. This type of spotting can happen with any type of birth control. But it’s more likely if you take ultra-low-dose birth control pills or have an IUD. It’s also common in women who:

  • Smoke
  • Miss a pill
  • Take continuous dose pills to skip periods
  • Use emergency contraception

Polycystic ovary syndrome

Polycystic ovary syndrome, or PCOS, is caused by a hormonal imbalance. It happens when your body produces more male hormones than normal. “Those extra hormones, called androgens, lead to cysts on the ovaries, which can prevent ovulation,” Gressens says. And that lack of ovulation can lead to irregular periods.


When uterine tissue grows in other places besides your uterus, it’s called endometriosis. Your body needs to get rid of that excess uterine tissue. “Shedding that extra tissue can affect the length of your cycle, making it longer, irregular or more painful,” says Gressens.

Pelvic inflammatory disease

An untreated sexually transmitted infection typically causes pelvic inflammatory disease. When that infection spreads throughout your reproductive system, it can change how your uterus sheds its lining. Those changes can cause lighter or heavier periods, bleeding or spotting after sex, pelvic pain and foul-smelling vaginal discharge.


Fibroids are growths in your uterus. Because these growths can thicken the uterine lining, they may cause heavier bleeding. Fibroids can also cause spotting between periods or longer cycles.

Thyroid conditions

Producing too much (overactive) or too little (underactive) thyroid hormone can alter your menstrual flow. You may notice that it gets heavier or lighter. Your cycle may also become unpredictable.


Perimenopause is a transition before menopause begins. It can last anywhere from two to 10 years. During this time, periods become more irregular. As hormone levels fluctuate, your cycles may become longer or shorter. Periods may also get lighter or change in frequency.

Other causes of irregular periods:

  • Too much exercise
  • Stress
  • Significant weight loss or gain
  • Cervical or uterine infections
  • IUD expulsion
  • Taking blood thinners
  • Breastfeeding
  • Uterine or cervical cancer

Making the diagnosis

To find the reason for your bleeding, your provider might order testing, including:

Pelvic ultrasound

A technician takes images of your uterus and ovaries during a pelvic ultrasound. This helps find possible abnormalities that can cause abnormal bleeding.


Lab tests can check for hormonal imbalances that may impact your menstrual cycle.

Pap smear

During a Pap smear, your provider takes cells from the cervix. Those cells are examined under a microscope for changes that indicate cervical cancer or other conditions.


During this procedure, a technician removes a small piece of tissue from your uterus and views it under a microscope. This helps find abnormalities that might be causing irregular bleeding.


During this procedure, your provider will use a special tool to look at the inside of your uterus. It helps find abnormalities that may cause bleeding.

Treatments for irregular periods

Once your healthcare provider finds the cause of your menstrual irregularities, they can help you find the right treatment. Options they may suggest include:

Oral contraceptives

Birth control pills can help regulate hormone levels, making periods more predictable. The pill can also lighten your flow and make your period shorter.

Tranexamic acid

This medication is used to treat heavy menstrual flow. It helps your blood clot, which can reduce the amount you pass each month.

Hormone replacement therapy

As you approach perimenopause, your hormones change. This shift can make periods more unpredictable. To help, your provider may suggest using supplemental hormones. Hormone replacement therapy can include just estrogen or a combination of estrogen and progestin. You can take them in one- or three-month intervals to regulate bleeding and ease symptoms.


If fibroids or cysts are causing painful periods, your provider may recommend surgery to remove them. And if other treatments don’t help, or your bleeding is extreme, your provider may recommend a hysterectomy to remove your uterus and stop menstruation altogether.

Put a stop to things

Whatever the reason behind your bleeding, your provider will be there to help. Once your bleeding issues get fixed, you can stop worrying about them. And get back to focusing on the things you love.

Next steps:

Learn about women’s health services at Geisinger
Anxiety at the gynecologist? Here’s how to beat it
Looking for birth control? Learn about your options.

Content from General Links with modal content