Some women may experience a missed period, and this can happen for many reasons, including a medical condition, medication or stress and lifestyle factors. With a one-off period that's missed, we may not find out the cause and hopefully your cycle returns to normal. Persistent missed periods will need investigating with your doctor.
If you are sexually active and you missed your period, pregnancy would be high on the list of reasons, especially if you are inconsistent with contraception. Even if you are on contraception and taking it correctly, there is still a small risk that you could be pregnant. Stress on the body both physically and mentally can affect your period, causing them to be delayed. Fluctuations in your weight (underweight and overweight), chronic diseases (such as thyroid disease) or doing too much exercising can affect the hormones needed for ovulation. Up to 1 in 10 women experience polycystic ovarian syndrome (PCOS). This is where the ovaries contain a large number of underdeveloped follicles which are unable to release an egg. This affects ovulation and can cause delays in periods. Contraceptive medications can affect your periods. It is not unusual whilst on contraception to occasionally miss a period. This isn't usually a cause for concern. Some types of progesterone-only medications like the implant or the coil can stop your periods altogether but they soon return on stopping the medications. As oestrogen levels start to decline towards the age of 50, your periods will change, becoming irregular or stopping altogether. This is called the menopause. If it happens before 40, this is called premature ovarian failure and needs investigating by your doctor.
If you are sexually active and you miss your period, it is important to do a pregnancy test. If you have no other symptoms and a negative pregnancy test, it might be worthwhile waiting for your next period cycle to see if your period resumes. If your period has not resumed after three cycles, it would be good to speak with your doctor. It is important to address any lifestyle factors that may be affecting you. Stress is an insidious cause of changes to your body and if not addressed can continue to impact you in a number of ways. Ensuring that you are a healthy weight and eating well-balanced nutritious meals and drinking plenty of fluid is also important.
Your doctor will discuss your medical history, sexual history and family history with you, and they will ask about any recent stressful events. They will consider your age, how long this has been going on and any other symptoms that you may be experiencing. Depending on the likely cause, your doctor will either advise you to watch and wait for the time being or ask you to do some further investigations. This includes checking your weight, arranging some blood tests, and possibly organising an ultrasound scan of your womb and ovaries. If there is any further concern, they can refer you to a specialist for further review and investigation.
The treatment of a missed period depends on the underlying cause. For example, if it is due to PCOS you may be advised to start contraceptives to regulate your hormones and cycle. If it is due to an underlying chronic condition like thyroid disease or diabetes, you may be advised to take medication to get this under control. If it is due to menopause, your doctor may discuss the options available such as considering hormone replacement therapy.