What could be Causing My Irregular Periods?

Irregular periods can be annoying. But unfortunately, they can also be a symptom of a more concerning underlying health issue. If your period isn’t consistent in length from cycle to cycle, it could be related to something benign, like stress, or it might be a sign of an autoimmune disease. If you’re experiencing cycle irregularity, you should talk to your doctor. But in the meantime, continue reading for an understanding of the various reasons behind irregular periods.

An irregular period is any menstrual cycle shorter or longer than 21 days or 35 days (respectively) for consecutive months. Your menstrual cycle begins on the first day of your period and lasts until the first day of your next period. The average cycle length is 28 days, but ACOG considers anything between 21 and 35 days normal.

If the length of your cycle varies each month by 7 to 9 days, you could be considered irregular. Spotting between cycles and bleeding lasting longer than a week are irregular symptoms.

You know your body best and likely understand what is normal for you and what is not. However, cycle tracking can be a great way to better understand your reproductive health.

If your period is consistently regular for longer than three cycles (or three months), it’s best to contact your doctor. They will likely be able to help you determine possible causes of irregular periods and how to get your cycle back on track.

Conditions affecting your reproductive system

Conditions that affect your reproductive system often produce menstrual symptoms like irregular periods. Polycystic Ovarian Syndrome (PCOS), Pelvic Inflammatory Disease (PID), and Endometriosis are all linked to cycle inconsistencies. Most of them result from hormonal issues, but some also involve factors concerning reproductive tissues and organs. Conditions like PCOS or PID share other symptoms, too, such as painful periods, infertility, and abnormal bleeding.

Medications

Certain medications, namely steroids and anticoagulant meds (known as blood thinners), may result in an inconsistent menstrual cycle. Generally, periods are only impacted when you use the medications long-term. Period delay or prolonged bleeding occurs because the steroid impacts the hormones responsible for ovulation and menstruation.  

Birth control

You likely know that birth control can affect your cycle. After all, the medication is taken to alter ovulation and implantation so that pregnancy does not occur. Different types of birth control can result in various symptoms. Some forms of the pill, like low-dose progestin-only, may be less likely to cause irregular periods than a combination pill or ring. Going on the pill or coming off the pill usually results in changes to your period. Period irregularities can last six months or longer, even after you stop taking birth control.

Thyroid problems

Specific autoimmune diseases, like thyroid conditions, cause your hormones to fluctuate. Hormonal imbalances then affect other bodily processes, such as menstruation. Gland disorders that may result in an irregular period include hyperthyroidism (overactive thyroid), hypothyroidism (underactive thyroid), and pituitary conditions.

Pregnancy, breastfeeding, or miscarriage  

Ectopic pregnancy is when the fertilized egg implants somewhere outside your uterus. When you’re pregnant, your period typically stops. Ectopic pregnancy, however, may not completely halt your period. Instead, you might experience irregular periods and spotting. Miscarriage causes your hormones to fluctuate, disrupting normal ovulation and menstruation.

Women who are breastfeeding typically experience irregular periods too. Prolactin, which triggers milk production, works to prevent ovulation. Without ovulation, periods don’t regularly occur. Some women might see a return of their period while nursing. In contrast, others won’t resume menstruating until after they’re done breastfeeding or pumping.

Medical procedures

Any procedure that affects your uterus, fallopian tubes, or ovaries can disrupt your menstrual cycle. Surgery that results in scarring or blockages to these areas might cause delayed, missed, or absent periods.