Amenorrhea

Causes of and treatments for amenorrhea

Woman sat next to a potted plant wondering if she might have amenorrhea

Key takeaways

  • Amenorrhea is when a woman doesn't have periods when she normally would do

  • Primary amenorrhea is when a woman has never started having periods. Secondary amenorrhea is when a woman has started having periods which then stop

  • When caused by things like pregnancy or menopause, secondary amenorrhea is not unexpected, but it can also be a symptom of underlying health problems

  • Secondary amenorrhea may be treated with hormone medications or with lifestyle changes

Contents of this article

Amenorrhea is the medical term for absent periods. There are two types of amenorrhea. The first type is primary amenorrhea which is when a woman’s periods don’t start by the time they would normally be expected to. Secondary amenorrhea is when a woman who has had periods in the past stops having them. Although there are natural reasons for a lack of periods such as pregnancy and breastfeeding, amenorrhea can sometimes be a sign of an underlying condition.

What is amenorrhea?

Although women don’t have periods before they go through puberty, during pregnancy or after the menopause, if a woman doesn’t have periods when she could normally expect to, the medical term is amenorrhea. In some cases it could be due to an underlying condition.

What is the difference between primary and secondary amenorrhea?

If a woman doesn’t start having her periods by the age of 16, she can be described as having primary amenorrhea.  In most cases, it’s not something to worry about. Girls start their periods from the age of 12 onwards and periods will start at the latest by the age of 18. If you’re worried about starting your periods late, or concerned about your daughter, you can always speak to your doctor.

Secondary amenorrhea is when you’ve been having periods but they stop for no apparent reason. It’s officially amenorrhea when you haven’t had a period at all for three or more months. The first thing you might want to do is take a pregnancy test as an unexpected pregnancy could explain an absent period.

What causes amenorrhea?

Natural reasons such as pregnancy, breastfeeding and menopause are all common reasons for amenorrhea. If you’re not pregnant, breastfeeding or going through the menopause, another common reason for disappearing periods is hormonal contraception.

If you use a contraceptive implant or coil, or have contraceptive injections, you may find that you get irregular periods or they stop altogether. This can also happen if you take the mini-pill, although it’s not as common. You should find everything returns to normal when you stop using the hormonal contraception. If you haven’t had a period within six months of stopping using hormonal contraception, you should speak to your doctor.

Other reasons for secondary amenorrhea include:

  • Stress and/or depression
  • Poor diet
  • Certain drugs
  • Extreme weight loss
  • Sudden weight gain and/or obesity
  • Exercising too much
  • Hormonal imbalances - sometimes due to polycystic ovarian syndrome (PCOS)
  • Thyroid gland disorders
  • A condition called Hyperprolactinaemia.

Premature ovarian failure

If you are still young enough to be ovulating but your ovaries have stopped producing eggs, this is called Premature Ovarian Failure. It’s thought to happen to around one in every 100 women before the age of 40, and the number rises to one in every 20 before the age of 45.

Sometimes, premature ovarian failure is caused by a problem in the immune system which can make it attack the ovaries.  You can also experience premature ovarian failure if you’ve had chemotherapy or radiotherapy.

You should seek medical advice if you think you have premature ovarian failure, even if you're not concerned about having periods.

What is post pill amenorrhea?

Post-pill amenorrhea is the medical term for not starting periods again after coming off hormonal contraception. In most cases it’s a relatively uncomplicated medical problem to diagnose and treat, and many doctors won’t suggest treatment unless you’re trying for a baby. If you’re trying to get pregnant there are medications that can help to get your periods started again.

What is hypothalamic amenorrhea?

Your menstrual cycle is regulated by a part of the brain called the hypothalamus. It produces the hormones that tell your ovaries to release eggs. Hypothalamic amenorrhoea happens when the hypothalamus stops sending the hormones to the ovaries, stopping the menstrual cycle.

Hypothalamic amenorrhea has been linked to excessive weight loss, and is sometimes seen in women who have an eating disorder like anorexia nervosa. Athletes, dancers and women who exercise excessively for weight control can also be affected.

Sometimes, stress or a long term illness can affect the hypothalamus and cause amenorrhea. Poorly managed diabetes is one example.

If you have the symptoms of hypothalamic amenorrhoea you should always speak to your doctor because it can lead to brittle bones (osteoporosis).

How can amenorrhea be treated?

For primary amenorrhea, most doctors prefer to ‘wait and see’ as most girls will start their periods naturally by the age of 18.

In some cases, absent periods can’t be treated, usually if there’s an underlying condition. In some cases, lifestyle changes can help, and for some medical conditions, there are effective treatments.

Polycystic ovary syndrome (PCOS) can be treated with hormones, often the contraceptive pill or another hormonal treatment containing progesterone.

If your amenorrhea is caused by hyperprolactinaemia, a condition where there are abnormally high levels of a hormone called prolactin, medication can be taken to treat it.

If weight loss, exercise, stress or a long-term condition is causing the lack of periods, you will probably be given advice on lifestyle changes. If you’re an athlete, you might be referred to an expert in sports medicine who can give you advice on keeping your fitness levels up without losing your periods.

If you have an eating disorder, such as anorexia, you’ll be referred to an appropriate counsellor for help.

Hormone medication is often given to women with premature ovarian failure. This could be hormone replacement therapy (HRT) or taking the contraceptive pill. Progesterone cream is not a suitable treatment.

If your periods have stopped because of a thyroid condition, this can be treated with medication that either stimulates or slows down the thyroid.

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