Periods which stop (Amenorrhoea) or are irregular (Oligomenorrhoea)

Periods can temporarily stop and usually this isn’t a problem. If it happens, check if you are pregnant and that you are feeling generally well. If so it’s fine to wait and see what happens. If it has been going on for longer than 3 months check in with your doctor.

Everyone starts their periods at different times. If you are older than 16 and still haven’t started your periods or if you are 14 and haven’t yet got any signs of puberty (breast development, underarm or pubic hair) see you doctor to discuss it further.

Periods can also be unpredictable. If you bleed between your periods or after sex, or after the menopause, you should discuss this with your doctor.

What are the causes for periods to stop or become irregular?

During pregnancy. Periods normally stop when you are pregnant and restart about 6 weeks after you baby is born.

During breastfeeding. If you are exclusively breastfeeding, you may not have a period until you stop. When you reduce breast feeding you may start to have bleeds again.

After menopause. The menopause is the time in your life when your ovaries stop producing eggs and you stop having periods. The average menopause is around the age of 51.

Contraceptives. Some types of contraception may stop periods. This doesn’t happen for everyone but it is normal to miss periods(or for them to get much lighter) if you are using:

  • The progestogen-only pill (POP)
  • The intrauterine system (IUS) – sometimes called a Mirena, Kyleena or coil.
  • A progestogen contraceptive injection. (depo)
  • A progestogen contraceptive implant. (Implanon)

Stress – Stress can affect your hormones (chemical messengers). This can lead to messages to your ovaries temporarily stopping. Usually if this is the case, they will restart naturally over time.

Low body weight – Losing large amounts of weight may result in periods stopping, especially if your BMI drops below 19. Anorexia nervosa can do this. It may also happen to athletes, gymnasts, endurance runners, and ballet dancers.

Polycystic ovary syndrome (PCOS) – PCOS is common and can lead to irregular and infrequent periods known as oligomenorrhoea. Women with PCOS may have other symptoms such as difficulty losing weight, spots (acne) and too much body hair.

Hormone problems 

A number of conditions which affect hormone levels may cause periods to stop. This includes:

  • High prolactin levels often caused by a growth called a prolactinoma.
  • Thyroid problems.
  • Congenital adrenal hyperplasia. This is a rare inherited condition affecting the adrenal glands and the way they produce steroid hormones.
  • Cushing’s syndrome.
Genetic Factors

These are conditions which are due to problems with the building blocks of our cells and can be inherited through our families. Sometimes, girls who never start periods have a genetic condition called Turner’s syndrome. Sometimes abnormal development leads to a lack of ovaries, uterus or vagina and it’s only found when she is a teenager and hasn’t started periods when expected.

Early menopause

On average women in the western world stop periods at the age of 51 but this can vary. When periods stop before the age of 40, this is early described as premature menopause or premature ovarian insufficiency.

Medical treatment

Hysterectomies will stop periods as the uterus is removed. An endometrial ablation for heavy periods may temporarily stop bleeding but it can recur. Chemotherapy can also stop periods. Illicit drugs such as heroin may also stop periods.

Getting back to normal after stopping contraception

When you have been on a pill or an injection for contraception, it may take a couple of months for your body’s natural cycle to resume and periods to restart.

What should I do if I have not started my periods?

Girls all start periods at different ages but speak to your doctor if:

  • You are over 16 and haven’t started periods.
  • You are over 14 and have no puberty changes
  • You have pains every month but no bleeding.
  • You can feel a lump in your pelvis.
  • You have had sex without using contraception and could be pregnant.
  • You have lost weight or have symptoms of anorexia nervosa.
  • You don’t feel well.

What should I do if I have had periods which have now stopped?

Usually this is nothing to worry about, check that you aren’t pregnant and if you feel ok otherwise just wait and see. Speak to a doctor if:

  • You usually have regular periods but haven’t had one for three months.
  • You usually have irregular periods and haven’t had one for 9 months.
  • You are pregnant.
  • You want to become pregnant.
  • You are less than 45 and have menopause symptoms.
  • You have lost weight, or your BMI is 19 or less.
  • You or someone close to you is concerned about your eating or weight.
  • You have milk leaking from your breasts and are not breastfeeding.
  • You don’t feel well (eg. headaches, visual changes, have lost or gained weight).
  • You have stopped the pill and haven’t had a period for 6 months or have stopped the depo injection and haven’t had a period for 12 months.
  • You are worried about your lack of periods.

Will I need any tests?

If you go to see a doctor about this problem, they will start by asking you some questions. They will want to know:

  • When you started periods and what they were like.
  • How long it has been since you had a period.
  • What contraceptives you have used.
  • If you are taking medication or have any other medical conditions.
  • If you have recently lost weight.
  • If you are under any stress.
  • If you could be pregnant.
  • Any other symptoms, such as hot flushes or milk leaking from your breasts. (Hot flushes may suggest an early menopause; milk leaking from your breasts suggests high levels of the hormone prolactin, discussed above.)

Your doctor will then examine you. They will usually work out your BMI by checking height and weight. They may feel your abdomen. They will look for signs of possible causes. (For example, excess body hair suggesting PCOS, or a lump in the neck indicating possible thyroid problems.) Sometimes, an internal examination may be needed.

Next steps will then depend on what has been discovered from talking to you and examining you. You may not need any tests at all. Tests could include:

  • A pregnancy test (urine sample).
  • Blood tests. These are done to check out a number of possible causes. They may check hormone levels (such as thyroid hormones and prolactin, or the levels of hormones linked to the ovary). Occasionally tests for genetic causes may be needed.
  • An ultrasound scan. (This can check your internal organs are normal, especially if you and your doctor wish to avoid an internal examination. This might be the case, for example, in young girls who have not started their periods.)
How are absent periods treated?

This depends on the cause. Often no treatment is needed.

Are there any complications of missed periods?

In the short term, there are no complications but if it goes on for a while it may cause problems.


If you don’t have periods it may be a sign that you are not ovulating. If this is the case it would be hard to become pregnant. There are treatments to help with this so discuss it with your doctor if you want to become pregnant.

Weak bones (osteoporosis)

If your periods stop because your oestrogen level is low you will also be at risk of weakening bones. This places you at a higher risk of fractures and can lead to a condition called osteoporosis. This is the case if you haven’t had a period for over a year.

Heart disease

Low oestrogen levels may also increase the risk of heart disease. Women with PCOS are at risk of metabolic syndrome where they have a propensity towards high blood pressure, diabetes and a high cholesterol. Lifestyle management is very important for these women

Irregular periods

Other patterns of periods which are different to normal may also occur, as follows.

Infrequent periods

Having big gaps between periods is known as oligomenorrhoea. The most common cause is PCOS.

Erratic periods

For some women, periods are unpredictable. This is more common in teenagers starting their periods and may go on for a few years as hormones settle down. It is also common in women approaching the menopause. If no cause is found, it is known as ‘dysfunctional uterine bleeding’. If bleeding is heavy, or the erratic cycle is a problem, there are treatments which can help, so see your doctor. See our heavy periods blog for more information.

Bleeding between periods

There are many causes for bleeding between periods. It is common in the first 2-3 months after starting the combined oral contraceptive (COC) pill.

In all other circumstances, see your doctor if you have bleeding between your periods or bleeding after sex. You will need an examination and possibly some tests to find out the cause.

Please consult with an Integriti GP who will be able to help you.

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