Late and irregular periods

An irregular period is when your period comes earlier or later than regular periods.

Regular periods start between 3 and 5 weeks from the start of your last period. Irregular periods are often related to other period problems.

There are many lifestyle and medical reasons your period might be late or irregular.  

Lifestyle can have a big effect on your body, and your health — that includes your period. These are a few common lifestyle reasons your period might be late or irregular:

• Stress has an effect on your hormones, as well as the part of your brain that controls your period — the hypothalamus. Stress is the most common cause of irregular periods
• Sudden changes in body weight can be pretty dangerous for your body — fast weight loss can stop ovulation
• If you exercise too much, or if you are ramping up the amount you exercise too suddenly, your periods may stop
• Shift work. Working evenings and nights can affect your internal biological clock — and your period
• Travelling to different time zones can affect your internal biological clock and hormones. Your period will likely go back to normal when you settle
• Sometimes it can take time for your period to return to a regular cycle after coming off contraception such as Depo Provera or the pill

There are lots of medical conditions that affect your period. These are a few common medical reasons your period might be late or irregular:

• A late period is often an early sign of pregnancy. If you think there is a chance you might be pregnant: get a pregnancy test or make an appointment with us
• Eating and exercise disorders — such as anorexia — are very dangerous for your body. Low body weight, or fast weight loss, can stop ovulation
• Polycystic ovarian syndrome (PCOS) upsets your hormone levels. Small cysts can form on your ovaries when you have PCOS. These cysts sometimes lead to irregular ovulation, or even stop ovulation. If you notice other signs of PCOS — such as more hair on your face and body, or bad acne — you should make an appointment to talk with one of our nurses or doctors
• Menopause usually begins between 45 and 60. Late or irregular periods can be a sign that menopause is starting
• An overactive or underactive thyroid gland can cause late or irregular periods

If you only have three or four periods a year, or if you continue to have irregular periods, or if you have bleeding between your periods or after having sex, make an appointment with us.