What are irregular periods?

Irregular periods are periods that don't follow a typical pattern. They might:

• come earlier than expected
• come later than expected
• be shorter than usual
• be longer than usual

Irregular periods can be frustrating because:

• you may not have period products when you need them
• it can also be hard to plan for pregnancy

What is a normal menstrual cycle?

How long your period lasts and how often you get your period is different for everyone.

A normal menstrual cycle can range from 21 to 35 days. Your menstrual cycle begins on the first day of your period. It continues until the first day of your next period. Your period (when you bleed) usually lasts from 3 to 7 days.

If you always have about the same number of days between periods, your menstrual cycle is regular. The average menstrual cycle length is 28 days.

What symptoms are related to irregular periods?

Any change in your normal menstrual cycle may be a cause for concern. A change in your cycle could be:

• you have a period more often or less often than is normal for you
• your bleeding is heavier than usual (heavy periods)
• your bleeding is lighter than usual
• your period is longer or shorter than is normal for you
• you have spotting (bleeding) between periods
• your period does not come at all (amenorrhoea)

What causes irregular periods?

It's normal for your period to be irregular for a year or 2 after your first period. In most people, periods will eventually become regular. However, some people never get a regular cycle.

Your period can be irregular:

• after childbirth
• after a miscarriage
• after a termination (abortion)
• in the years leading up to menopause (perimenopause)

It's very important to check if you are pregnant, before starting hormonal contraception.

There are many other things that may affect how often you get your period, such as:

• doing a lot of exercise
• excessive dieting
• sudden weight loss or weight gain
• having polycystic ovarian syndrome (PCOS)
• being stressed
• starting or changing hormonal contraception
• taking some medicines

How is the cause of irregular periods diagnosed?

Your doctor will ask about your symptoms and may do an examination.

It's a good idea to keep a record about your period using a diary or phone app. For example, make a note of:

• when you get your period
• the length of your period
• the heaviness of your period
• when your period stops

Take this record to your appointment to talk about with your doctor.

Your doctor can arrange tests to find out what may be affecting your periods. They may also refer you to a gynaecologist (specialist doctor who manages conditions that affect the female reproductive system).

When should I see my doctor?

It's important to see your doctor if you are worried about your menstrual cycle. You should also see your doctor if you have any of the following:

• you have not had a period for 3 months or more
• you have had less than 9 periods in a year
• you have not started your period by the time you are 16 to 17 years old
• you have bleeding between periods
• you have bleeding after sex

Your doctor should do their best to listen to you and take your concerns seriously. If this doesn't happen, do not be afraid to find a new doctor with an interest in women's health.

How are irregular periods treated?

Because there are so many possible causes of irregular periods, your treatment will depend on the likely cause.

Self-care at home

A healthy lifestyle can help regulate your menstrual cycle. This includes:

• eating a balanced diet
• reducing stress
• getting enough sleep
• exercising regularly

Medicines for irregular periods

The oral contraceptive pill ('the pill') can help make your periods regular.

In females with PCOS, a medicine called metformin can help treat irregular periods.

Complications of irregular periods

Getting pregnant can be more difficult because you might not ovulate (release an egg) regularly.

Resources and support

Learn more about the menstrual cycle on the Jean Hailes for Women's Health website.

If you have any concerns about your periods, go to your doctor or local sexual health clinic.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with 24 hours a day, 7 days a week.