Amenorrhoea can be primary or secondary. Primary amenorrhoea refers to no menstruation by age 16 with normal secondary sexual characteristics, or by age 14 in females with no secondary sexual characteristics.
Secondary amenorrhoea is the absence of periods for three to six months in a female who previously had periods.
Find out when the last period was and consider common physiological causes, such as pregnancy, menopause or lactation. Is the patient concerned about infertility?
Ask about menstrual history; ask about how heavy or light the periods were and how many days the cycles lasted. Ask also about previous pregnancies, and whether they have been trying to become pregnant.
Take a full contraceptive history, as recent cessation of contraceptives can result in delayed menses. Ask about specific symptoms of menopause, such as hot flushes. It is also worth asking if there is a family history of premature ovarian failure or early menopause.
Consider pituitary symptoms and ask about galactorrhoea, headaches and visual disturbance. Are there symptoms of polycystic ovary syndrome (PCOS), such as acne, hirsutism or weight gain? Ask about diet and exercise, as weight loss, anorexia and heavy exercise can result in amenorrhoea. Certain drugs can cause amenorrhoea, such as some antihypertensives and antipsychotics, so it is important to ask about medications. Ask the patient about previous gynaecological procedures or diagnoses and about symptoms that may suggest thyroid disease.
Check BMI and do a pregnancy test at baseline. Look for any signs suggestive of pituitary disease, such as galactorrhoea, and for signs of PCOS.
Observe for signs of virilisation, such as hirsutism, acne, deep voice, temporal balding, increase in muscle bulk, breast atrophy and clitoromegaly. These are signs of excessive androgens that can occur as a result of PCOS, androgen-secreting tumours or Cushing's syndrome. Observe for signs of thyroid disease.
A detailed pelvic examination and speculum examination may be necessary. It is important to examine the abdomen for any masses suggestive of pregnancy or tumour.
Useful blood tests to aid diagnosis include FSH and LH to look for menopause; SHBG, LH and testosterone for PCOS; prolactin for pituitary causes and TSH for thyroid disease.
If hormone tests are abnormal, it is good practice to repeat the blood tests, especially with sensitive diagnoses, such as premature ovarian failure.
If blood tests and examination are normal, a trial of a combined oral contraceptive can help aid the diagnosis. If the woman has a period as a result, the cause is likely hypothalamic-pituitary dysfunction, ovarian failure or estrogen excess.
Management of amenorrhoea depends on the cause. Hypothyroidism and PCOS can be managed in primary care. Bone protection may be required in patients with long-term estrogen deficiency, such as premature menopause.
More complex diagnoses, such as Cushing's syndrome or pituitary disease, will require specialist referral. Where appropriate refer to fertility services according to local and national guidelines.
Patients may require emotional support from their GP or a counsellor.
- Dr Raymond is a GP and women's health teaching associate at Royal Free and University College London Medical School