7 Common Causes of Menstrual Irregularities and When to Seek Medical Attention

A typical menstrual cycle lasts anywhere from 21 to 45 days, with the average being about 28. But some people experience irregular periods on occasion or throughout their lifetimes. If you’ve always had an unusual or irregular cycle, it may be nothing to worry about. But if you’re experiencing sudden or unexpected changes in your cycle, it could indicate a problem.

If you’re experiencing any changes in your cycle, like missed periods, spotting, or lighter or heavier flow, there could be a reason. If you’re experiencing new or unusual discharge, pain, more intense cramping, it could be something serious. Here are some of the common causes of menstrual irregularities and when to seek medical attention.

1. Pregnancy

If your period is late or if you’ve missed a period completely, your first thought is likely pregnancy. If there’s a possibility you could become pregnant or you suspect you might be, it’s a good idea to take a pregnancy test. This is true for anyone who’s been sexually active, even if you used protection.

Over-the-counter pregnancy tests can provide accurate results as soon as one day after a missed period. If your cycle is typically somewhat irregular, you can take a test about three weeks after having sex. Follow up with a healthcare provider to confirm the results of any drugstore tests.

2. Your Birth Control

Maybe you’ve accidentally missed a few doses, skipped your placebo week, or otherwise been inconsistent with your birth control pills. Any kind of disruption in the recommended dosage or timing of your pills can cause menstrual irregularities.

If you’re on the pill, do your best to make sure you’re sticking to the pill’s instructions. You can use the timer on your phone or invest in an electronic pill case that automates reminders. If you’re taking your pill correctly and still having irregular periods, consider switching to a pill like junel fe, that’s designed to help regulate your periods.

3. Hormonal Imbalance

Certain kinds of hormonal imbalances can cause irregular periods, among other frustrating symptoms. Polycystic ovary syndrome and thyroid disorders are two of the main hormonal culprits in causing irregular periods.

PCOS typically causes other symptoms like abnormal hair growth, thinning hair, obesity, and acne. Thyroid disorders are numerous, and the symptoms are more complex and varied. They often develop slowly over many years, and can be hard to spot. If you suspect any kind of hormone-related disorder, speak to your healthcare provider about getting a proper diagnosis.

4. Other Medical Conditions 

Other medical conditions can also cause missed periods or menstrual irregularities. These can include uterine fibroids, clotting disorders, STIs, and, in some cases, cancer. Eating disorders, especially if a lot of weight is lost (see below), can lead to missed or absent periods.

Missed periods or spotting can be a sign of uterine, ovarian, and cervical cancers. Other symptoms can include pelvic pain, changes in vaginal discharge, and painful intercourse or bleeding after sex. If you have signs, symptoms, or any reason to suspect any of the above medical conditions, see a healthcare provider. 

5. Medications

Many, many medications can cause menstrual irregularities, missed periods, or changes in menstrual flow. One of these medications is the progestin-only pill, or mini-pill, which can cause spotting or bleeding between periods. Epilepsy medications, thyroid drugs, chemotherapy and even antidepressants are also among the medications that can cause menstrual irregularities.

Warfarin, aspirin, and other anticoagulants and antiplatelet drugs can cause changes in blood flow, including heavier menstrual bleeding. Speak to a healthcare provider right away if you notice extremely heavy bleeding or bleeding between periods on these medications.

6. Weight Changes or Excessive Exercise

While some hormone changes that cause weight gain or loss can also affect your periods, sometimes weight change alone can cause irregularities. If you’ve been exercising much more heavily than usual, or lost or gained weight, it could impact your periods. Gaining weight can make your periods heavier, and losing it can make them lighter.

Overexercise can cause you to skip some periods or to miss your periods entirely. In endurance athletes like runners and gymnasts, missed periods can indicate a condition like relative energy deficiency in sport (RED-S). With RED-S, the body doesn’t get enough energy to meet the demands placed on it, potentially causing serious long-term health consequences.

7. Perimenopause

If you’re at or approaching a certain age, missed periods or menstrual irregularities could be a sign of perimenopause. This is the stage of life in which your body starts to transition toward menopause. In perimenopause, estrogen levels dip and your fertility begins to decline. You may also experience other symptoms like lower libido, night sweats, and vaginal dryness.

Perimenopause typically begins between the ages of 40 and 44. But it can occur as early as your 30s or as late as your 50s. Once perimenopause begins, menopause usually occurs about 8-10 years later. Some medical conditions can cause premature perimenopause or menopause. 

When to Seek Medical Attention

Menstrual irregularities are very often an indication that something is a little “off” with your health. A slightly late period could just be an indicator that you’ve been a little stressed. More serious irregularities can be an indicator of more serious medical issues. It’s always a good idea to seek medical attention if anything seems outside of your “normal.”

If you are having extremely heavy periods, especially if you’re on blood thinners, speak to a healthcare provider right away. Call 9-1-1, or go to the emergency room if you experience intense pelvic pain. Severe bleeding, pain, or cramping can be signs of a medical emergency like an extrauterine pregnancy or ruptured ovarian cyst.