What Causes Abnormal Menstrual Cycles?

Black woman confused about when to see a doctor about abnormal menstrual cycles.

It can be frustrating to keep track of your menstrual cycle. Sometimes your period is right on time doing exactly what you expect it to do, but other times it shows up late, and the bleeding is irregular.

It’s normal to feel worried if abnormal menstrual cycles are becoming more frequent for you. Often times there’s nothing to feel anxious about, but sometimes irregular bleeding can be the initial sign of a serious medical condition. That’s why it’s always vital to listen to your body, and educate yourself on what it could be trying to tell you.

We’re breaking down the biggest culprits of irregular periods below and when you might need to head to your doctor’s office.

General Life Events Causing Abnormal Menstrual Cycles:

There are a handful of events that happen during a woman’s life that will trigger a difference in menstrual bleeding. Keep these in mind if you’re trying to rule out a medical condition.


Often the first sign of pregnancy is missing your period. Spotting is also a common symptom for women who are pregnant, and women who breastfeed also see reduced periods. Pregnancy is an amazing medical event that touches so many parts of a woman’s life, so it’s only natural that it also impacts that person’s menstrual cycle.

However, every woman experiences pregnancy differently. Speak with your gynecologist to figure out what is and isn’t normal if you’re worried about how much or how little you are bleeding during your pregnancy.

Birth Control / Medications

It’s extremely common that hormone-based birth controls can cause irregular bleeding, whether it’s spotting or causing your period to disappear altogether. If you’re concerned about your period and know you’re using birth control like an IUD or pills, then do some research, and see if it’s a common occurrence for your period to change. Also, make sure to speak with your gynecologist, and ask your questions. They are the experts in birth control methods.

Perimenopause and Menopause

Perimenopause is the period before menopause, mimicking similar symptoms and preparing the woman’s body for what is to come. Since both perimenopause and menopause are a shifting of women’s hormones, your period is one of the first things to become affected. Other symptoms include hot flashes, night sweats, mood changes, difficulty sleeping, and vaginal dryness.

If you know it’s about that time for you, then visit your doctor to learn what else to expect during this period. Or click here to learn more about menopause from the experts at Avant Gynecology.

Obesity or Weight Change

Being overweight impacts your hormones and insulin levels, therefore affecting the regularity of your periods. On the opposite end of the spectrum, extreme weight loss and over-exercising can also cause your period to change for the same reasons.

Speak with your doctor today to discover if your physical health is interfering with your period.


Abnormally high levels of stress are no fun, and it could also be impacting your menstrual cycle. When you’re stressed out, your brain begins to meddle with your hormones, including the ones that regulate your cycle. This can cause all sorts of issues, like weight gain and severe fatigue. But it can also increase or decrease the flow of your period.

If you’re feeling stress, help your body relax and get out of fight or flight mode by practicing relaxing techniques. Yoga, meditation, or baths can go a long way and get your body back on the right track.

If the problems continue to persist, contact your doctor to see what else you can do to assist your body.

Medical Conditions That Cause Abnormal Menstrual Cycles:

If you’ve ruled out all the above life-related options, here are some of the most common medical issues that cause changes in your menstrual cycle. All of these conditions will require an immediate visit to your gynecologist.

Polycystic Ovary Syndrome

This is a disorder that causes ovaries to become overly large and have small cysts on the outer edges. It most commonly affects women in the reproductive age. Aside from interfering with menstrual bleeding, it also causes weight gain, acne, infertility, depression, excess male hormones, and hair loss.

Thyroid Disorders

There are two common types of thyroid disorders: hypothyroidism, when the thyroid is underactive, or hyperthyroidism, when your thyroid is overactive. While the former causes heavier periods, more cramping, fatigue, cold sensitivity, and weight gain, the latter is known to cause lighter periods, weight loss, anxiety, and heart palpitations.

Uterine Fibroids

Uterine fibroids are non-cancerous tumor-like growths that grow in or on the walls of the uterus. They range in sizes, starting from somewhere as small as a seed to something as large as a baseball. Aside from being extremely painful, they also cause abnormal bleeding, pelvic pressure, lower back pain, and pain during sex. Click here to learn more about uterine fibroids from our experts.


A condition that makes the tissue normally inside of your uterus grow on the outside, endometriosis affects an alarming one in 10 women who are in their reproductive age. It most commonly causes changed bleeding patterns, extremely painful menstrual cramps, gastrointestinal pain, painful bowel moments, pain during and after sex, and even infertility.

Reproductive Cancers

Reproductive cancers, like uterine cancer, often cause irregular bleeding as a first symptom. Understanding the causes of cancer and potential means of prevention is one of the most important steps women can take for their health, which is why you should click here to learn more about reproductive cancers.

Issues Unrelated to your Reproductive Organs

Sometimes issues unrelated to your reproductive organs can also cause your menstrual cycle to be impacted. Such examples of these medical problems are liver disease, chronic kidney disease, and blood clotting disorders.

Having an irregular period can be concerning to experience. If you’re still not sure whether or not you should visit the doctor, click here to read more from us about when irregular bleeding is truly a cause of concern.

If you have more questions or would like to speak to a professional, click here to schedule an appointment with any of our talented and intelligent gynecologists.