Women's Health Matters

Text Size
Jump to body content

Missed or infrequent periods

Your period can be considered a vital sign. It’s a sign that your body is in a healthy enough state to support a pregnancy.

Cycle length and flow vary widely from one woman to another, so there is a range of healthy menstrual patterns. A regular menstrual cycle is usually between 25 and 35 days, but may be as long as 40 days.

The occasional blip in a cycle can be normal. However, infrequent, absent or very heavy periods are all types of abnormal uterine bleeding (AUB).

“Every month, things like travel, stress, or sometimes even being around different groups of people with different pheromones, can change the cycle a little bit,” says Dr. Yolanda Kirkham, a gynecologist at Women’s College Hospital. “So if it’s just one or two off periods, just keep track of that. But if there’s a pattern developing, you’ll want to talk to a doctor.”

Reasons to see your doctor include:

  • infrequent periods: if you only have a few periods per year
  • absent periods: if you’ve missed three or four periods in a row, or haven’t had a period in six months, and you are not pregnant
  • bleeding with no pattern at all, or bleeding every day for weeks
  • any bleeding after menopause
  • very heavy periods or large clots


If a woman is not pregnant, possible causes of missed or infrequent periods include hormonal factors. These are especially common in very young women, and in women approaching menopause.

When young women first start menstruating, it can take a couple of years for periods to become regular as their hormones establish a monthly cycle. In older women, periods may become more erratic during perimenopause (the years leading up to menopause) as the opposite process happens: hormones begin to wind down.

“Normally what happens is a woman will have regular periods, and then in the year or two leading up to the menopause, her periods will start to space out,” Dr. Kirkham says. “The definition of menopause is one full year with no periods. Any bleeding after a year of menopause is abnormal and needs to be investigated.”

Because these issues are hormonally driven, they are often managed using birth control pills and other hormonal contraceptives, which control and regulate the menstrual cycle, leading to healthy shedding of the uterine lining and reducing risks for uterine and ovarian cancer.

Weight factors

Other factors that can result in infrequent periods in young women may be related to weight, or body mass.

“On the very low end of the spectrum – for example athletes, or young women with eating disorders, or those who are under a lot of stress – their periods are absent or very infrequent because their body fat content is below normal,” Dr. Kirkham says.  “These women are usually expending more energy than they are taking in through food and nutrition.”

“At the other end of the spectrum of some overweight women, we often find polycystic ovary syndrome (PCOS). This can also be associated with unwanted hair or acne, and leads to infrequent periods, fertility difficulties, and possible diabetes and hyperlipidemia.”

Managing both of these types of irregularities often begins with lifestyle changes.

“Although they’re at different ends of the spectrum, both of those are actually nutrition and exercise-related, and those are the important targets of treatment,” Dr. Kirkham says. For example, in women with PCOS who are overweight, losing just 10 per cent of body weight can help restore regular periods.

Healthy lifestyle

The menstrual cycle is linked to overall health in all women, and things like medications or chronic illnesses can also affect periods. Dr. Kirkham stresses the importance of a healthy lifestyle – including balanced nutrition, fitness and not smoking – to overall reproductive health.

“I wish I could write these things on a prescription: eat well and exercise,” she says. “It’s not medication, but it’s actually good treatment.”


Jump to top page

Connect with us

Subscribe to our E-Bulletin

  • A publication of:
  • Women's College Hospital