Menstrual cycles that are too frequent may be a sign of a structural abnormality of the female reproductive system or hormonal imbalance, and periods that are too infrequent can be related to an undiagnosed pregnancy, hormonal imbalances that affect ovulation, or nutritional concerns. The majority of women’s cycles last 21 to 35 days, counting from day one of one cycle to day one of the next cycle, and their periods last five to seven days on average.
The combined hormonal contraceptives contain a good amount of progestins – synthetic progesterone – which limit the build-up of a lot of tissue lining the uterus resulting in a less flow pattern when the cycle usually occurs. In addition, painkillers like ibuprofen, antidepressants, thyroid medications, and steroids might shorten flow.
PCOS is a genetic condition where women overproduce amounts of male hormones, which can suppress ovulation and lead to changes in menstruation.
Primary ovarian insufficiency (previously referred to as premature ovarian failure) occurs when women have a loss of normal ovarian function prior to 40 years old. The ovaries aren’t working correctly, and won’t produce the right amounts of estrogen or release eggs when they’re supposed to, therefore leading to a shortened and irregular cycle.
Uterine scarring can also lead to shorter cycles. This is known as Asherman Syndrome, a rare condition that most often occurs in women who have had multiple dilation and curettage (D&C) procedures.
Breast feeding exclusively will not have a cycle while women are breastfeeding. The body is suppressing ovulation hormones by producing prolactin, alpha-lactalbumin, and lactose synthesis and when its stopped or decreased a normal cycle will return.
An overactive thyroid producing to much of thyroid hormones will provide feedback to the hypothalamus to slow down production, which also inhibits period regulating hormones. The result being infrequent cycles. Natural aging leads to shorter cycles, particularly around perimenopause, which typically begins in a woman's late 30s or early 40s.
Excessive stress will cause the hypothalamus of the brain to produce chemicals that trigger your pituitary gland to signal your ovaries to release estrogen and progesterone. Therefore, an increase in cortisol from stress, exacerbates this axis which causes the cycle to become disarray and produce less bleeding.
