Find out what's normal and what's not normal for your periods.
Amenorrhoea (absence of periods)
Amenorrhoea simply means an absence of your periods. Doctors usually classify amenorrhoea into primary or secondary amenorrhoea.
- Primary amenorrhoea: where your periods have never started and you are at least 16 years old.
- Secondary amenorrhoea: where you normally have periods but they have stopped for 6 months or more.
When is it normal not to have periods?
It is normal not to have periods:
- before you reach puberty;
- when you are pregnant;
- if you are breast feeding; and
- if you have reached menopause.
Causes of amenorrhoea
Amenorrhoea may be caused by:
- malfunction of the thyroid gland, the hypothalamus (part of the brain that helps regulate the menstrual cycle) or the pituitary gland;
- problems with the ovaries;
- anatomical problems with the uterus, cervix or vagina;
- delayed puberty;
- prolonged strenuous exercise;
- depression and some other forms of mental illness;
- low body weight;
- some medicines, including the oral contraceptive pill (it can take 3-6 months to start periods again after stopping the pill), certain antipsychotic medicines and cancer chemotherapies;
- chronic illness;
- hormonal imbalances such as polycystic ovary syndrome (PCOS); or
- premature menopause.
Dysmenorrhoea (painful periods)
Dysmenorrhoea means painful periods. Period pain and discomfort is usually most severe for the first day or so of your period. Dysmenorrhoea tends to peak quite soon after puberty, so if your periods are getting increasingly painful as you get older, see your doctor. Doctors usually classify dysmenorrhoea into primary or secondary dysmenorrhoea (see below).
Common symptoms of dysmenorrhoea include:
- pain in the lower abdomen and occasionally the upper thighs; and
Common symptoms associated with dysmenorrhoea include:
- nausea; and
- constipation or diarrhoea.
Occasionally you may have vomiting.
The symptoms, which do not last very long (usually around one to 2 days), are caused by prostaglandins, natural substances found in many body tissues. Prostaglandins stimulate contractions of the muscles of your uterus during your period. Experts believe these contractions of the uterus compress the blood vessels to the uterus, temporarily cutting off the blood supply and depriving the tissues of oxygen, which triggers pain.
Primary dysmenorrhoea may affect more than half of all women, and occurs with no known underlying cause. The pain in primary dysmenorrhoea occurs from the contractions of the uterus, caused by prostaglandins, described above.
Secondary dysmenorrhoea is caused by an underlying gynaecological problem or condition such as:
- pelvic inflammatory disease; or
- fibroids (growths in the uterus).
The use of intra-uterine devices for contraception (not including the intra-uterine levonorgestrel-releasing system Mirena) has also been associated with dysmenorrhoea and heavy bleeding.
Menorrhagia (heavy periods)
Menorrhagia means that periods are long and heavy. It is one of the most common causes of iron deficiency anemia in Australian women. Menorrhagia may include periods that are prolonged, lasting for longer than a week, or that involve excessive bleeding with 'flooding' or clots.
Women with menorrhagia lose 80 mL (4 tablespoons) or more of blood per period (equivalent to about 6 tampons per day for 4 to 5 days).
Causes of menorrhagia
Menorrhagia may be caused by:
- hormonal imbalances (e.g. in menstrual cycles where no egg is produced, which are more common in girls who have just started menstruating and women approaching the menopause);
- a bleeding disorder;
- polyps (small growths on the cervical or uterine wall);
- polycystic ovary syndrome (PCOS);
- thyroid disease;
- liver or kidney disease;
- infection (pelvic inflammatory disease);
- intra-uterine devices (IUDs), not including the intra-uterine system Mirena, which is, in fact, a treatment option for menorrhagia;
- some medicines, such as anti-inflammatory medicines and anticoagulants; or
- (rarely) cancer.
If you think you may suffer from amenorrhoea, dysmenorrhoea or menorrhagia, see your doctor who should be able to make a proper diagnosis and advise you of treatment options for your condition.
Last Reviewed: 16 March 2011
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3. Jean Hailes Foundation for Women’s Health. Menstrual cycle fact sheet (last updated Feb 2011). http://jeanhailes.org.au/resources/fact-sheets/ fact-sheet-by-topic/599-menstrual-cycle (accessed Jul 2011).
4. Family Planning NSW. The hormone-releasing IUD (Mirena) (reviewed Jan 2011). http://www.fpnsw.org.au/751201_8.html (accessed Jul 2011).
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6. Mayo Clinic. Menstrual cramps (updated 3 May 2011). http://www.mayoclinic.com/health/menstrual-cramps/DS00506 (accessed Jul 2011).
7. Mayo Clinic. Menorrhagia (heavy menstrual bleeding) (updated 25 Jun 2011). http://www.mayoclinic.com/health/menorrhagia/DS00394 (accessed Jul 2011).