What are irregular periods?

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

• come earlier or later than expected
• be shorter or longer than usual
• be heavier or lighter than usual

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.

What is a normal menstrual cycle?

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.

What symptoms are related to irregular periods?

Symptoms related to irregular periods include if:

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

What causes irregular periods?

Many factors can affect whether your periods are regular.

Lifestyle factors that may cause irregular periods include:

• lack of exercise
• sudden weight loss
• weight gain
• being stressed
• starting or changing hormonal contraception

Some medical conditions can cause irregular periods, such as:

• polycystic ovarian syndrome (PCOS)
• premature ovarian insufficiency (when your ovaries stop working at a younger age than usual)
• uterine polyps (small growths in the lining of your uterus)
• adenomyosis
• cancer

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:

• after childbirth
• during perimenopause (the years leading up to menopause)

When should I see my doctor?

It's important to see your doctor if you have any symptoms of irregular periods. This may include if you have:

• not had a period for 3 months or more
• had 8 or less periods in a year
• not started your period by the time you are 16 years of age
• bleeding between periods
• bleeding after sex
• periods that last longer than 7 days

See your doctor if you have irregular periods as well as other symptoms like:

• weight gain
• tiredness
• difficulty falling pregnant

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.

How is the cause of irregular periods diagnosed?

To diagnose irregular periods, your doctor may ask about:

• your menstrual cycle
• when your periods became irregular
• your sexual history
• your medical history
• any medicines you take

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:

• when you get your period
• the length of your period
• how heavy your period is
• when your period stops

Take this record to your appointment with your doctor.

Your doctor may arrange tests to find out what is affecting your periods, such as:

• a blood test
• a urine test
• an ultrasound scan of your pelvis
• a sexually transmitted infection (STI) test

Your doctor may also refer you to a gynaecologist. This is a specialist doctor who manages conditions that affect the female reproductive system.

How are irregular periods treated?

Treatment of irregular periods will depend on the 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
• maintaining a healthy bodyweight

Medicines for irregular periods

Some hormonal medicines can help regulate your menstrual cycle, including:

• the oral contraceptive pill ('the pill')
• the progestogen-only pill ('the 'mini pill')
• intrauterine devices (IUDs)

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:

• medicines to reduce bleeding — these include tranexamic acid and anti-inflammatory medicines
• iron supplements — these help treat low iron levels caused by heavy bleeding
• metformin — this can help treat irregular periods if you have PCOS

Before taking a medicine, ask your doctor or pharmacist if it's right for you.

Other treatment options

If other treatments do not work, your doctor may recommend surgery, such as:

• endometrial ablation
• endometrial resection
• a hysterectomy

It's important to discuss the risks and benefits of each procedure with your doctor before you decide.

What are the complications of irregular periods?

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:

• iron deficiency
• endometrial cancer
• cardiovascular disease — because of lower hormone levels with irregular periods

Talk to your doctor if you have any questions about complications and if they might affect you.

Resources and support

The Jean Hailes for Women's Health website offers information on:

• irregular periods
• premenstrual syndrome (PMS)
• heavy periods
• different types of period pain

The Australian Institute of Health and Welfare page has information on menstrual disorders including irregular periods.

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.