Menstrual periods may be irregular due to a woman’s age, exercise habits, stress levels, diet or health problems, according to WebMD. If a period starts and stops and restarts in the same day, it may be due to birth control methods or a hormonal imbalance. When an individual misses her period for a month or two, the reason may be due to other causes.
Most women have a period every 28 to 35 days with normal variation. Periods occurring less than 21 days apart or skipping two or three months indicates that there is a reason the periods are being affected. One of the most common is stress, according to the Cleveland Clinic, and generally, when the stress goes away, the periods return to normal. Weight loss or gain also affects period regularity. Diets that drastically reduce calories are prime culprits. Athletes with heavy endurance routines may experience missed periods also.
Medications such as birth control pills affect hormonal levels in a woman’s body, according to WebMD. The changing hormonal levels are enhanced when birth control pills are used on an intermittent basis. When this happens, irregularities in the menstrual cycle may persist for months. Normal variance associated with menopause affects periods. Many women experience skipped periods for a year or more before their periods stop altogether. Usually, an absence of menstruation for one year indicates menopause.
Conditions such as fibroids, endometriosis and polycystic ovary syndrome may also interfere with period regularity and flow. If periods are irregular, it is best to consult with a physician.