Irregular Cycles

Irregular menstrual cycles is a common issue that affects women and can interfere with fertility. A normal cycle occurs every 24 to 35 days and lasts 7 days or less.


Women with cycles that occur less frequently than every 35 days (oligomenorrhea) should be evaluated with laboratory studies and a pelvic ultrasound. Laboratory studies that are typically checked include a pregnancy test, thyroid studies (TSH & T4), prolactin (PRL) and total testosterone (T). Women who have an overactive thyroid (hyperthyroidism, low TSH) or an underactive thyroid (hypothyroidism, high TSH) can have infrequent menstrual cycles or frequent, heavy menstruation and are at risk for infertility, miscarriage and preterm labor. Women that have an elevated prolactin level may not release an egg (ovulate) each month and may have headaches or narrowed vision. Over the short term they are at risk for infertility and over the long term women may experience the effects of low estrogen including vaginal dryness or a higher risk of fracture from thin bones (osteopenia or osteoporosis). Women with elevated levels of total testosterone may experience infrequent cycles and hair growth in areas they typically would not expect (hirsutism) including the face, chin, chest or abdomen. Women with abnormal thyroid function, elevated prolactin or elevated testosterone levels can be treated with medications and will often see a reversal in symptoms within 1 to 2 months.


Women who have cycles that occur more frequently than every 24 days or lasting longer than 7 days may become frustrated with the amount and severity of their bleeding. In addition to having their thyroid function checked (TSH, T4) and a pelvic ultrasound, they should have a complete blood count (CBC) performed to check for a low red blood cell count (anemia). Underactive or overactive thyroid function and anemia can be treated with medicine.