Irregular Periods | Jean Hailes

Irregular periods are periods that don't follow a typical pattern. They might:
Irregular periods can be frustrating because they are unpredictable. You may not have period products when you need them. It can also be hard to plan for pregnancy.
Irregular periods affect about 1 in 5 women of reproductive age.
How long your period lasts and how often you get your period is different for everyone.
A menstrual cycle can range from 21 to 35 days. Your menstrual cycle begins on the first day of your period and continues until the first day of your next period. If you always have about the same number of days between periods, this means your menstrual cycle is regular.
A typical period usually lasts 3 to 7 days.
Read more about menstruation.
Many factors can affect whether your periods are regular.
Lifestyle factors that may cause irregular periods include:
Some medical conditions can cause irregular periods, such as:
It's normal for your periods to be irregular when they first start. They usually become regular after a few years.
Your period may also be irregular:
It's important to see your doctor if you have any symptoms of irregular periods. This may include if you have:
See your doctor if you have irregular periods as well as other symptoms like:
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.
Read more about how to find the right health professional.
To diagnose irregular periods, your doctor may ask about:
Your doctor may also examine you.
It's a good idea to keep a record about your period using a diary or phone app. For example, make a note of:
Take this record to your appointment with your doctor.
Your doctor may arrange tests to find out what is affecting your periods, such as:
Your doctor may also refer you to a gynaecologist. This is a specialist doctor who manages conditions that affect the female reproductive system.
Treatment of irregular periods will depend on the cause.
A healthy lifestyle can help regulate your menstrual cycle. This includes:
Some hormonal medicines can help regulate your menstrual cycle, including:
It's very important to check if you are pregnant before starting hormonal contraception.
Other medicines can help treat the symptoms of irregular periods, such as:
Before taking a medicine, ask your doctor or pharmacist if it's right for you.
Irregular periods can cause complications, especially if your period is heavy or continues for a long time.
Getting pregnant can be more difficult if you have irregular periods. This is because you might not ovulate (release an egg) regularly.
Other complications that could be linked to irregular periods include:
Talk to your doctor if you have any questions about complications and if they might affect you.
The Jean Hailes for Women's Health website offers information on:
The Australian Institute of Health and Welfare page has information on menstrual disorders including irregular periods (Opens in new tab).
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 you 24 hours a day, 7 days a week.
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Last reviewed: March 2026

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