Longer periods can be caused by hormone fluctuations that arise from anything from stress, the food you eat to the medication you’re taking and frequent travel.

Any one of these components can alter your physiological state and as a result, send your cycle out of sync.

Sometimes, longer periods can be an indication of something serious that requires medical attention, and at other times, they are not anything to worry about at all.

While there are a number of reasons that cause your periods to run longer than usual, we round up five of the most common ones.

READ MORE: 5 things that could be making your period pain worse

  • Polycystic Ovarian Syndrome (PCOS)

Polycistic Ovarian Syndrome (PCOS) is a hormone disorder that affects about 10% of women. It is characterised by very lengthy or irregular periods and it can lead to infertility.

If you experience heavy bleeding in conjunction with other symptoms of PCOS, including weight gain, suddenly developing facial hair on your face, or migraines, then it’s advisable that you consult your gynaecologist. Early diagnosis and treatment is important.

  • Thyroid gland changes

Around 30% of women in their late-30s to mid-40s experience changes in their thyroid gland and this can cause longer or heavier than usual periods. The most common type of thyroid disease is hypothyroidism, which occurs when your body doesn’t produce enough thyroid hormone.

Fertility specialists says this isn’t a cause for concern, but you should still consult your doctor.

  • Pregnancy or miscarriage

We all know that some women experience periods throughout their pregnancy, but did you know that a longer period can also indicate a pregnancy?

READ MORE: Five things your period could be saying about your health

Bleeding during a pregnancy can also be a sign that you’ve had a miscarriage.

  • You’re ovulating

According to Dr Sherry Ross, gynaecologist and author of She-ology, it is possible to bleed at the same time as an egg is being released. This is known as intermenstrual bleeding and can occur as a result of a hormone imbalance, stress, cancer, a growth in your uterus or cervix or a change in medication.

If this intermenstrual continues for longer than three months, you must consult your doctor.

  • IUD

If you’re suddenly experiencing longer periods and you recently an intrauterine device (IUD) installed, it could be as a result of the device. Longer periods are most associated with copper IUDs and tend to occur in the first few months after having it inserted.

Additional reporting: Bustle, Mayo Clinic