Ladies, you’ve heard about the 28-day menstrual cycle. Is it accurate, or is it a myth? Many women find themselves wondering if they’re “normal” if their cycles don’t follow the 28-day rule. What do you think?
What Studies Show
A study of more than 600,000 women found that just 13% had a 28-day cycle. For a fact we’ve heard so many times, that’s surprising. While we’ve come to accept the 28-day rule as a standard, many individualized factors go into determining how long your menstrual cycle is, or should, be.
Factors That Affect Menstrual Cycles
The average length of menstrual cycles around the world, according to the study, is between 29 and 35 days. However, this isn’t true for all women across the board. Elements such as BMI, age, ethnicity, and even stress come into play.
It’s shown that women with higher BMIs have longer cycles, and that chronic stress can lead to delayed cycles. Even something as simple as a change in diet can change the length of a woman’s cycle. Most women also don’t have identical cycles every month.
Irregular Menstrual Cycles
Anywhere from 14%-25% of women report having irregular menstrual cycles. Conditions such as polymenorrhea, where a woman’s cycle is less than 21 days, is an example. Or Polycystic Ovarian Syndrome (PCOS), a condition where ovulation is disrupted, can cause significant variances in women’s cycles.
Pelvic Inflammatory Disease, endometriosis and uterine fibroids can also lead to irregular cycles. There’s a large number of women affected by these conditions, and therefore experience cycles that are either longer or shorter than 28 days.
Nearly 10% of women struggle with PCOS alone, and another 10% will be diagnosed with endometriosis in their lifetimes.
When to See a Doctor
While the 28-day cycle may be a myth, and the length of your cycle may vary slightly from month to month, if you notice significant changes, it’s time to see a doctor. There are many causes of irregular periods, and often a simple test can help determine what’s going on in your body.