Irregular periods

An irregular period can be different for everyone and is usually defined as a period that is unlike your usual experience in some way. For you, this could look like:

• heavier bleeding than normal
• lighter bleeding than normal
• a later period than expected
• a shorter period than normal
• more pain than you are used to
• less pain than normal
• a missed period

What is a regular period?

Typically, a regular period happens every 28 days but it is common for them to be more or less frequent. The normal range is 21 to 35 days and bleeding can last 2 to 7 days. You may know from experience what frequency counts as ‘regular’ for your periods.

A regular period may also include a normal amount of bleeding and period pain for you, consistent with previous periods.

Irregular periods can often be caused by natural changes in hormone levels and is nothing to be worried about. This is common during puberty and when nearing menopause (perimenopause). If you’re experiencing an unexplained change in your period or are finding them hard to manage, speak to your doctor.

Medication

Hormonal contraception such as the mini pill, the implant, and the intrauterine system (IUS) are progesterone-based and can stop your period all together, they also can cause heavy or irregular bleeding, and affect people differently. Other contraception such as the combined pill, contraceptive injections, and the contraceptive patch can lead to lighter bleeding.

Other non-hormonal contraception, such as the copper IUD, also called the copper coil, can make periods irregular and lead to bleeding between periods. A common side effect of this type of contraception is heavy periods and pain for the first few months.

Chemotherapy can lead to missed periods as it can cause early menopause. This can be temporary but your doctor may recommend seeing a fertility specialist.

Other medications that can affect your period:

• anticoagulants (blood thinners) such as aspirin or warfarin
• thyroid medication
• hormone therapy

Pregnancy and breastfeeding

Irregular periods can be a sign of pregnancy. When you’re pregnant your periods will stop completely. It’s possible to have a bleed occasionally while pregnant but if you experience heavier bleeding and cramps during your pregnancy you should speak to your doctor or midwife for advice.

After you have given birth, your period may stay irregular for some time until your hormones return to normal. If you are combining breastfeeding with bottle feeding, or are only bottle feeding, your period could return as soon as 5 or 6 weeks. If you are only breastfeeding, then your period may not return until you reduce breastfeeding.

If you’ve missed a period and you think it’s possible you could be pregnant, take a pregnancy test.

Weight

If you have a low body weight you may experience irregular periods or they may even stop completely as the body does not have enough fat to produce the hormones for menstruation. Being overweight can also cause irregular periods due to an increase in some hormones like oestrogen.

Maintaining a healthy balanced diet, exercising regularly, and managing stress can all help you lose weight or keep you at a healthy weight which can help you to regulate your period. However, excessive and intense exercise can also be a cause for irregular periods.

Medical conditions

Certain medical conditions can contribute to irregular periods.

Endometriosis

Endometriosis is a condition where tissue that lines the womb (uterus) grows in other parts of the body, such as the pelvis or ovaries. This can lead to:

• heavier, more painful periods
• pelvic pain
• fatigue
• painful bowel movements
• pain during or after sex
• difficulty getting pregnant

If you are experiencing any of these symptoms you should speak to your doctor.

Polycystic ovary syndrome (PCOS)

Polycystic ovary syndrome can cause irregular periods as it affects the ovaries ability to release eggs. PCOS is a chronic condition that leads to small cysts on the ovaries caused by the over creation of hormones known as ‘androgens’. Other symptoms include:

• weight gain
• excessive hair growth
• oily skin or acne

You should speak to your doctor if you think that PCOS may be causing your irregular periods.

Fibroids

Fibroids are noncancerous growths made of muscle and fibrous tissue. They are primarily found in the womb and can vary in size. Fibroids can cause heavy periods with clots and bleeding between periods. Large fibroids can cause some pain or discomfort in the back or pelvis.

Thyroid conditions

Your level of thyroid hormones can lead to heavy, irregular, or missed periods. The hormones that control the thyroid and the ovaries are secreted from the same area of the brain meaning that if you have an underactive thyroid (hypothyroidism) or overactive thyroid (hyperthyroidism) you may have an irregular period.

Stress

High levels of stress can cause your body to release hormones like cortisol and adrenaline. This can affect the balance of oestrogen and progesterone, the hormones that regulate your period. This can then lead you to have late or missed periods, which can be more painful.

Stress can also lead to worse premenstrual symptoms like fatigue, mood swings, and bloating.

Effectively managing an irregular period will depend on what is causing it. Often, simple lifestyle changes can help to regulate your period. Simple lifestyle changes you can make are:

• eating a balanced diet and maintaining a healthy weight
• managing stress and anxiety, this can be done through meditation, yoga, or regular exercise
• getting enough sleep
• limiting caffeine and alcohol

If you’re having pain during your period, you can try taking over-the-counter pain medications (ibuprofen or paracetamol), heat therapy, or light exercise, such as swimming or yoga.

If your irregular periods are caused by an underlying health condition, you should speak to your doctor to find a solution that will work for you. They may recommend medications such as the combined contraception pill to help regulate your period.

Irregular periods every now and then are not a cause for concern and do not usually require treatment. However, you should see your doctor if you:

• experience an irregular period for no apparent reason
• are bleeding between periods or have heavy periods that last longer than 7 days – this could be a sign of an infection
• are over the age of 65 and are still having your period, or if you have stopped having periods and are under the age of 45

If you have had unprotected sex and have missed a period you should take a pregnancy test as you may be pregnant. If you have missed 2 or 3 periods but have a negative pregnancy test, you should see your doctor as it may be a sign of hormone changes.