What is PMT?
Almost every woman suffers from some form of Pre-Menstrual Tension (PMT), also referred to as Pre-Menstrual Syndrome (PMS) during the two weeks before their period is due.

For the majority, common PMT symptoms such as mood swings, breast tenderness, bloating and headache, are usually very mild and cause no real problems or disruption to daily life. However, some women have more severe symptoms that cause distress every month.

According to a recent survey, PMT is thought to affect up to 60 percent of Irish women. It tends to appear in the 20s and 30s and disappears around the time of the menopause. While there are no known risk factors, a family history of PMS may make it more likely that you will suffer from it too.

The cause of PMT is not fully understood. Many believe it is caused by individual sensitivity to normal hormone levels during ovulation rather than to a hormonal imbalance. Diet and psychological factors such as stress and emotional concerns have also been put forward as possible causes.

What are the typical symptoms of PMT?

PMT is characterised by a number of psychological, physical and/or behavioural changes. Symptoms are linked to the menstrual cycle and tend to start seven to ten days before your period begins and stop within 24 hours. Symptoms may vary from cycle to cycle and from woman to woman.

Physical symptoms

• Abdominal bloating
• Cramps
• Nausea
• Swollen ankles
• Weight gain
• Headache
• Breast tenderness
• Tiredness
• Backache

Psychological/behavioural symptoms

• Irritability
• Mood swings
• Poor concentration
• Anxiety
• Depression
• Fatigue
• Confusion
• Aggression
• Craving for sweet things

For some women (around 3-8 percent) the symptoms of PMT are severe enough to interfere with their home life, work and relationships. Very severe PMT symptoms (referred to as Pre-menstrual Dysphoric Disorder or PMDD) are experienced by 3-8 percent of women.

A diagnosis of PMDD requires the presence of at least 5 symptoms of PMT, mainly relating to mood, which appear 5 - 10 days before menstruation and cease within a few days of the onset of a period. The symptoms must be severe enough to interfere with work, family and social life.

In some cases symptoms attributed to PMT are due to a disease affecting the ovaries or womb. If your symptoms are severe or you are worried, consult your GP.

Are my hormones to blame?

Because PMT symptoms begin during the second part of the menstrual cycle, after ovulation takes place, it is believed that hormonal changes have a large part to play.

A woman's monthly cycle lasts between 24 and 35 days. During the first half of the cycle, the hormone oestrogen steadily rises. Oestrogen levels fall off around the time of ovulation but rise again after ovulation when the ovary begins to produce a hormone called progesterone. The level of progesterone rises to a plateau about 7-10 days after ovulation when it starts to fall. Progesterone levels are lowest just before a period begins.

Progesterone may cause water retention. For these reasons, hormonal changes during the menstrual cycle have been blamed for causing PMT.

Evidence suggests that reduced levels of the neurotransmitter (brain chemical) serotonin, have a role in PMT and, especially in PMDD. It is thought that when oestrogen levels drop, serotonin levels also drop. This evidence is based on a number of studies in which drugs called selective serotonin reuptake inhibitors (SSRI) were used to treat PMDD.

The main SSRIs studied were fluxetine and sertraline. Some of the woman were given placebos (tablets with no drug in them); others were given genuine SSRIs. The results showed that 20 percent of the women on placebo improved but 75 percent of women taking the SSRI showed improvement. SSRIs, however, are not without their own unpleasant symptoms. Side effects include insomnia, gastrointestinal disturbance and fatigue. A number of women withdrew from the studies because of these.

Does my diet influence symptoms?

Many studies have pointed to the benefits of a healthy diet in preventing both the physical and psychological symptoms of PMS. Include plenty of cereals, fruits, vegetables and wholegrain bread in your diet. Avoid sugary and high-fat foods such as chocolate and sweets. Salty foods should be avoided, especially in the second half of the cycle, as they encourage water retention.

Women with mild symptoms may find that increasing the amount of vitamins and minerals in their diet relieves their symptoms. But before you rush out to the chemist for supplements, have a look at your diet and see where you can increase your intake of these vitamins and minerals naturally. Some doctors prescribe vitamin B6 and magnesium.

There is very little objective information on the use of high doses of vitamin B6 in the treatment of PMS. Vitamin B6 is a cofactor in the synthesis of serotonin so, theoretically, it should be useful if the theory of reduced serotonin levels as a cause of PMS and PMDD is correct.

Alcohol may exacerbate some of the symptoms of PMS such as depression and headache so it is best to limit your intake, especially during the two weeks before your period is due. Caffeine should also be avoided as it is a stimulant and may increase irritability.

Increased intake of vitamins A and E and calcium also helps many women with mild symptoms. A number of studies have shown symptomatic relief in severe cases of PMS when calcium supplements were prescribed.

Some women find that certain foods such as chocolate and high caffeine drinks aggravate their symptoms so you should avoid these during your period and in the two weeks prior to the beginning of your period.

What treatments are available?

While treatment options are limited, the good news is that you can take steps yourself to relieve the symptoms of PMT.

Evening primrose oil capsules and starflower oil capsules are a popular, natural remedy with many women. If you are feeling tense and irritable, it can help to find an outlet in the form of exercise or therapeutic support such as yoga and meditation. Both exercise and relaxation will help relieve stress, which adds to the severity of PMS.

Painful cramps, backache and headache can be treated with painkillers such as paracetamol, mefenamic acid (ponstan), taken in the second half of the cycle can relieve. Some women take diuretics to relieve the discomfort of fluid retention.

In more severe cases, your GP may prescribe the oral contraceptive pill to help control hormonal fluctuations. Older women may benefit from HRT patches but certain types of HRT can cause symptoms to recur.


SSRIs and tricyclic antidepressants are effective in treating some cases of PMDD. SSRIs show benefit when given either continuously or intermittently (during the second half of the cycle).