Irregular periods are menstrual cycles that fall outside the typical range of every 21 to 35 days. Most women experience some changes in their cycle at different points in life, and not every shift is cause for concern. But when you have an irregular period for more than a few months, it often points to a potential health problem. Understanding the common reasons behind cycle changes can help you decide when it is time to see a provider.
What “Irregular” Actually Means
A regular cycle is not necessarily 28 days. Cycles between 21 and 35 days are considered normal for adults, and teens may have cycles up to 45 days apart for the first few years after their first period. Irregular periods can mean cycles that come too close together, too far apart, last too long, or vary widely from month to month. Missed periods, very light bleeding, or unusually heavy flow also fall into this category.
Hormonal Shifts Behind Irregular Cycles
Your menstrual cycle depends on a delicate balance of hormones, including estrogen, progesterone, and other hormones made by the ovaries, thyroid, and pituitary gland. When any of these get out of balance, your cycle can become unpredictable. Hormonal birth control, recent pregnancy, breastfeeding, and switching contraceptive methods can also throw off your usual rhythm for a few months.
Polycystic Ovary Syndrome
PCOS is one of the most common causes of irregular periods in women of reproductive age.
