The term oligomenorrhea is used to describe the condition of having an infrequent menstrual period. This clinical term is used when a woman has a menstrual period once every 35 days or longer. Most women with the condition menstruate only four to nine times a year. A "normal" menstrual cycle usually is between 21 to 35 days long, which means that this condition indicates an abnormal, or irregular, menstrual cycle.
Diagnosis of oligomenorrhea usually begins with a complete medical and menstrual history. For this, a doctor most likely will ask the patient to track her menstrual cycle over the course of a few months to determine the actual length. A new cycle begins on the first day of menstrual bleeding. For women who have difficulty tracking their cycles, there are numerous resources available online for recordkeeping. Other women choose maintain a calendar or chart.
Numerous conditions can cause oligomenorrhea, ranging from lifestyle circumstances to serious medical issues. It could occur when a woman is entering menopause and undergoing hormonal changes. A woman might also experience a long menstrual cycle when under extreme stress or after tremendous weight loss. Women with eating disorders sometimes experience long, or even absent, menstrual cycles. Female athletes or those who exercise intensely or excessively also can experience oligomenorrhea.
Several serious medical conditions can cause oligomenorrhea, including polycystic ovary syndrome (PCOS). Polycystic ovary syndrome is characterized by high levels of male hormones and cysts on the ovaries. Some outward symptoms of the disorder include excessive acne, hair growth and weight gain or obesity. Polycystic ovary syndrome can lead to type 2 diabetes or infertility. If a woman is diagnosed with oligomenorrhea, her doctor most likely will check her for signs of PCOS.
Some other possible causes of an excessively long menstrual cycle include pituitary disorders and Graves' disease, which affects the thyroid. In some cases, estrogen-secreting tumors can cause the condition. Any hormonal imbalance might disrupt the menstrual cycle.
The course of treatment depends on the underlying condition. Often, doctors will use hormone therapy or birth control to normalize hormones levels and reestablish menstruation. For women during certain life cycle phases, such as adolescence or menopause, it is normal for menstruation to be irregular, and these women will not require treatment. In the case of more serious medical conditions, surgery could be necessary to remove tumors. Some women with polycystic ovary syndrome also choose to undergo surgery to induce ovulation.