What Causes Irregular Periods? - Crozer-Keystone Health System - PA

Irregular Periods

Women’s bodies are forever changing. From time to time, every woman suspects that her menstrual cycle is abnormal for one reason or another. It’s important to remember that each woman’s cycle is different, so your “normal cycle” may not be the same as your best friend’s “normal cycle.” There are, however, some common reasons for a period to be irregular. 

Because each woman’s cycle is different, and because there are so many factors that cause an irregular cycle, it can sometimes be hard to pinpoint an exact reason for the irregularity. Periods are often irregular during the first couple of years of menstruation. This is because the body is still developing the delicate hormonal balance that leads to a regular cycle. Another common cause of an irregular or missed period is pregnancy.

What Causes Irregular Periods?

If you are not pregnant, other common causes of an irregular period include:

  • Excessive weight loss or gain: although low body weight is a common cause of missed or irregular periods, obesity also can cause menstrual problems
  • Eating disorders, such as anorexia or bulimia
  • Increased exercise: missed periods are common in endurance athletes.
  • Emotional stress
  • Illness
  • Travel
  • Medicines such as birth control methods, which may cause lighter, less frequent, more frequent, or skipped periods or no periods at all
  • Hormone problems: this may cause a change in the levels of the hormones that the body needs to support menstruation
  • Illegal drug use
  • Problems with the pelvic organs , such as imperforate hymen, polycystic ovary syndrome, or Asherman’s syndrome
  • Breastfeeding: many women do not resume regular periods until they have completed breastfeeding. 

If, for any reason, your period is irregular, you should contact your healthcare provider. It’s always best to be proactive when it comes to your health, something women can often forget when running their busy lives. Getting something checked out can help to prevent serious health conditions later on down the road.

Treatment Options for Irregular Periods

Although treatment depends on what is causing your missed periods, there are a number of common treatment options that can help regulate your cycle. Some of the most common options for women with irregular periods include:

  • Maintaining ideal body weight
  • Weight loss if you are overweight
  • Weight gain if you are underweight
  • Eating more calories if you suffer from eating disorders
  • Decreasing excess and/or strenuous exercise
  • Stress reduction 
  • Birth control pills
  • Medicines that help with pregnancy and fertility
  • Hormones if you are going through early menopause
  • Surgery if you have problems in the reproductive system

Warning Signs of an Oncoming Period

So, if your cycle is irregular, how can you tell when you're about to get your period? Below are some clues your body may give you, according to the National Institutes of Health:

  • Back cramps or stiffness
  • Heavier breasts or breast soreness
  • Headaches
  • Acne breakouts
  • Disturbed sleep patterns
  • Mood swings
  • Bloating 


Women may also find that their menstruation cycle is changing before menopause. Women can experience age-related menstrual changes as early as their 30's. Some of the changes that women can experience include:

  • A change in periods - shorter or longer, lighter or heavier, with more or less time in between
  • Hot flashes and/or night sweats
  • Trouble sleeping
  • Vaginal dryness
  • Mood swings
  • Trouble focusing
  • Less hair on head, more on face. 

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