Premenstrual Syndrome is a disorder that is experienced by 30-40% of women at some time during their reproductive years and has interesting features in common with my previous subject of postnatal depression.

A link was first reported by a French doctor in the mid 19th century who observed that some women with post natal depression experienced a worsening of symptoms prior to menstruation.

In the USA in the 1940s patients with puerperal psychosis were observed to show the same swings, becoming worse after ovulation, then improving after the start of the following period. Both of these observations suggested a hormonal link.

The description ‘PMS’ was first introduced in the early 1930s to describe ‘a state of unbearable tension’ prior to menstruation. Later, the term PMT (pre-menstrual tension) was restricted to a common symptom complex within PMS – the triad of tiredness, depression and irritability.

These were extended over time to include a long list of symptoms: the most common being bloating, water retention and resulting weight gain, breast tenderness, headaches, fatigue, anxiety and mood swings.

What type of PMS do you have?

More recently PMS has been divided into four sub groups based on the main symptom:

1) PMS-A for Anxiety, irritability, mood swings, nervous tension and increased appetite.

2) PMS-C for Cravings, headache, fatigue, dizziness and palpitations.

3) PMS-D for Depression, tearfulness, forgetfulness, confusion and insomnia.

4) PMS-H for Hyperhydration (fluid retention and weight gain, swollen ankles, abdominal bloating and breast tenderness).

To perhaps make it more confusing, to these sub-divisions we can add three extra categories of mild, moderate and severe, and even a new name of ‘Premenstrual Dysphoric Disorder’. This applies to the most severe form of PMS with the primarily emotional symptoms of depression, irritability, anger and aggression.

Fortunately only 5% of menstruating women have this degree of PMS but it significantly affects their day-to-day functioning.

The most common of these categories are said to be PMS-A and PMS-H, but of course in real life things are not often so well defined.

PMS can present itself with any combination of 150 symptoms, caused by a varying combination of factors.

Another complication is that a woman’s response to her own hormonal cycle is extremely individual. This is part of the reason it has been so difficult for doctors to agree on the causes of PMS, which at last is being recognised as a serious problem.

Guidelines of diagnosis and treatment have been published by NAPS (National Association for Premenstrual Syndrome) and also in great detail by the Royal College of Obstetricians and Gynaecologists (RCOG)

How is it diagnosed?

Whatever the combination of symptoms, for a diagnosis of PMS three criteria related to the timing of symptoms have to be present. The symptoms must:

1. appear in the last two weeks of the menstrual cycle (the luteal phase)
2. begin to resolve within the first few days of the next period
3. be absent during the rest of the first two weeks of the cycle (the follicular phase)

If this pattern is not present, then PMS is not the diagnosis and there are no tests or investigations that ‘prove’ it. Diagnosis is made entirely from the patient’s story and for accurate diagnosis the RCOG recommends the use of a menstrual diary over at least 2-3 cycles.

For many years, because PMS symptoms occurred around a peak in the progesterone levels in the latter (luteal) part of the menstrual cycle, it was assumed that progesterone was the cause of the symptoms.

However, the peak level is typically around the 21-22nd day of the cycle, after which it falls very abruptly, leading to menstruation. The hormone oestrogen has a peak in both halves of the cycle, but there is a much more gradual fluctuation.

The fact that the first of these peaks is in the first half of the cycle, when by definition no symptoms are present, suggests that it is in fact the fall in progesterone that is a major factor.

This mirrors the picture described in my previous articles on postnatal depression and psychosis, and may be reflected in a milder and much more gradual degree in the pre menopause.