Common Causes of Irregular Menstrual Cycles
Written By Kelcie Rosendahl, ND
A normal menstrual cycle is a reflection of a woman’s overall vitality. Some doctors have even proposed that the menstrual cycle should be considered the “fifth vital sign”, arguing that it is as important as having a healthy blood pressure, heart rate, temperature and respiratory rate. There are variations to what a “normal” cycle is from woman to woman. Often times “normal” is what is normal for you. The length of your cycle, amount of blood, color of the blood and frequency of bleeding can tell you a lot about your health.
Irregular menstrual cycles can be caused by a variety of factors including stress and lifestyle, use of hormonal birth control, breastfeeding, polycystic ovarian syndrome (PCOS), uterine polyps or fibroids, endometriosis, pelvic inflammatory disease (PID) or premature ovarian failure. You should check in with your trusted healthcare provider should your periods suddenly stop for more than 90 days and you are not pregnant, you bleed for more than 7 days in a row, you bleed more heavily than usual, your periods become less than 21 days or more than 35 days in length, you develop severe pain during your period, your periods become irregular after being previously regular or you get a fever and/or feel ill after using tampons.
Let’s start with a breakdown of the monthly hormonal changes that occur during the menstrual cycle. The first full day of bleeding is considered day 1 of your cycle and the total length of your menstrual cycle is from the first day of one cycle to the first day of the next cycle. A normal cycle is between 21-36 days in length, with 28 days being the average length in most women. It is not uncommon for some women to occasionally have a longer or shorter menstrual cycle. The menstrual cycle is broken into follicular, luteal and ovulatory phases.
Days 1-14 are the follicular phase of the menstrual cycle. During this time ovarian follicles are developing in preparation to release a mature egg from the ovary. Estrogen is the dominant hormone during this phase and is responsible for building a thick endometrial lining for the egg to implant in.
Ovulation usually occurs somewhere between days 12-14 of the menstrual cycle. Luteinizing hormone (LH) spikes at this time due to increased estrogen levels and causes an egg to be released from the follicle. The now ruptured follicle secretes progesterone and estrogen to continue to prepare for pregnancy.
The luteal phase begins following ovulation and is typically during days 15-28 of the menstrual cycle. Progesterone is the dominant hormone during this part of the cycle. Progesterone is responsible for maintaining an early pregnancy, avoiding miscarriage and optimizing fertility. If the egg is not fertilized, estrogen and progesterone levels drop, the endometrial lining sloughs off and menstrual bleeding begins. As I mentioned above, there are a variety of factors that can disturb this process and cause menstrual cycle irregularities. Some of the most common causes include the use of hormonal birth control, PCOS and endometriosis.
Hormonal birth control can have tremendous effects on the menstrual cycle. The pill, vaginal ring, patch, shot and IUD can all affect your period. Menstrual cycles can be longer, shorter, heavier or lighter depending on what kind of birth control you are using and your body’s response to the hormones. Irregular bleeding and spotting are common side effects of most forms of hormonal birth control. Interestingly, the bleeding you experience when taking a 21-day pack of birth control pills isn’t actually your period. The vaginal bleeding you experience during this week is called a “withdrawal bleed” and resembles a period but technically isn’t. This bleeding takes place because the hormones in the birth control pills decrease. Withdrawal bleeds are often lighter than the bleeding that occurs with a natural menstrual cycle.
PCOS, or polycystic ovarian syndrome, is a common culprit of irregular menstruation. In fact, irregular periods are the most common sign of PCOS. Other signs of PCOS include infertility, unwanted facial or body hair, male-pattern baldness, weight gain and blood sugar dysregulation. PCOS affects an estimated 10% of women of childbearing age. It most commonly develops during adolescence but can become an issue at any age after puberty. The exact reason why PCOS develops is unknown but it is thought that high levels of androgens (DHEA and testosterone) and insulin resistance play a role. PCOS is diagnosed by the Rotterdam criteria where two of the following three criteria must be met: 1) Hyperandrogenism: High levels of male hormones seen clinically or through laboratory evaluation 2) Oligomenorrhea: Cycles that are more than 35 days apart but less than 6 months apart 3) Polycystic ovaries: The presence of multiple cysts in the ovaries seen via ultrasound. Fortunately, there are both natural and conventional ways to successfully treat and manage PCOS.
Endometriosis is another common cause of irregular menses. Endometriosis is a complex condition that is caused when the tissue that normally lines the inside of the uterus grows outside of the uterus. Endometriosis affects a large number of women and can cause pain and infertility. Women with endometriosis have more tissue to shed during their menses which can result in period pain, decreased cycle length and excessive bleeding. Other symptoms of endometriosis include nausea, fatigue, pain during sexual intercourse, infertility and pain with bowel movements. The only definitive way to diagnose endometriosis is by a laparoscopy, an operation in which a camera is inserted into the pelvis with a small cut near the navel. The surgeon uses the camera to see the pelvic organs and look for any signs of endometriosis. If endometriosis is diagnosed, the endometriosis may be treated or removed for further examination during the laparoscopy.
Excessive period pain or bleeding is not normal. If you have concerns about your monthly cycle, I encourage you to seek help from your trusted healthcare provider. There is much that can be done for the conditions mentioned in this post and others that affect the health of your cycle. You do not have to live through agony each month and your period should not be something that causes you to miss out on the joys in your life!
The information on this blog is not intended or implied to be a substitute for professional medical advice, diagnosis or treatment.
References:
Rosenfield R. Definition, clinical feature and differential diagnosis of polycystic ovary syndrome in adolescents. UpToDate. http://www.uptodate.com/contents/definition-clinical-features-and-differential-diagnosis-of-polycystic-ovary-syndrome-in-adolescents?source=search_result&search=pcos&selectedTitle=4%7E150. Updated July 27, 2020. Accessed September 13, 2020.
Williams, Tracy, MD et al. Diagnosis and Treatment of Polycystic Ovarian Syndrome. American Family Physician. https://www.aafp.org/afp/2016/0715/p106.html. July 15, 2016. Accessed September 13, 2020.
Wei,Ming, MD et al. Length of Menstrual Cycle and Risk of Endometriosis. Medicine (Baltimore). 2016 Mar; 95(9); e2922. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4782879/
Birth Control and Your Period. The Society of Obstetricians and Gynecologists of Canada. https://www.yourperiod.ca/normal-periods/birth-control-and-your-period/.