Why are my periods irregular?

Irregular and frequent menstrual bleeding can be very debilitating. In a busy lifestyle, it affects today’s women even more. Even if the bleeding is not heavy, it still can cause chaos because of unpredictability. It includes too frequent periods (polymenorrhoea), irregular bleeding in between periods (intermenstrual bleeding) and bleeding after intercourse (postcoital bleeding).

How would I be examined to determine the cause of my irregular periods?

Any excessive bleeding, including when periods are regular but heavy (menorrhagia) is either due to a structural cause or a functional cause, such as the hormones playing up.

Structural cause

The structural cause is mainly from the uterus (womb), which includes the body of the womb and the cervix (the neck of the womb). Some minor bleeding can also be from the vagina and vulva. A clinician, therefore, would check the vulva for any obvious source of bleeding.

A vaginal speculum examination would follow to check the cervix. On inspection, obvious cancer (such as a ‘fungating’ mass or ulcer), a polyp (small localised swelling of the inner lining, endocervical epithelium) or ectropion (a raw red area that bleeds to touch or without provocation) would be visible. A swab from inside the cervix and, if necessary, a pap smear at the time would rule out infection (endocervicitis) or a precancerous condition.

While taking the speculum out, the vagina is checked and a high vaginal swab taken, if indicated. Prolapse of the womb leading to an ulcer or thinning of the tissues (atrophy) due to lack of oestrogen hormone after menopause can be present.

The main body of the uterus cannot be examined directly. Therefore, an internal ultrasound scan is done to exclude polyps, generalised swelling of the lining and fibroids that are protruding inside the cavity of the womb (submucous). Fibroids that are not ‘pushing into’ the cavity generally may cause heavy bleeding but not irregular. Rarely adenomyosis (endometriosis of the muscles of the womb) can be a cause.

A hysteroscopy (a small camera to look inside the womb) generally as an outpatient procedure without the need for anaesthetic or even a speculum, may be needed particularly in women over the age of 45.

Functional cause

If no structural cause is found from any of these examinations or investigations, the irregular bleeding is functional, i.e. due to the hormones fluctuating. Oestrogen thickens the lining of the womb, it’s withdrawal leads to it’s shedding (menstruation). This oestrogen comes from the ovaries but the ovarian hormones are controlled by hormones from the pituitary gland (behind the eyes). This, in turn, is controlled by hormones from the hypothalamus, a primitive structure deep inside the brain, that is not only involved with our survival instincts but also with emotion, exercise and appetite. Any alteration in any of these, particularly emotional stress can affect the hormones and therefore, periods because of a fluctuation in hormonal pulses in the hypothalamus.

How are irregular periods treated?

If there is a structural cause, it needs to be treated by either the removal of the polyp or fibroid or with oestrogen cream for atrophic vaginitis and thinning of the vagina. If it is hormonal, a steady dose of hormones, such as combined oestrogen-progesterone in young women and progesterone-only in elderly women (either as tablets or as the progesterone-coil IUS), need to be given to override the fluctuation of the hormones.

If you are concerned about your menstrual cycle, book to see a specialist.