Premenstrual syndrome (PMS): symptoms, diary and treatment

Premenstrual syndrome is the name for symptoms people can experience in the weeks before a period. The NHS notes that each person's symptoms are different and can vary from month to month, and that most women have it at some point. What makes it a syndrome rather than a passing mood is the cyclical pattern: symptoms arrive after ovulation, build towards the period and then lift.

NICE Clinical Knowledge Summaries make a useful distinction. Mild premenstrual changes are very common and are regarded as a normal physiological experience. PMS is the label used when the symptoms cause significant impairment to daily functioning during the luteal phase. The same guidance describes psychological symptoms such as low mood, anxiety, irritability, loss of confidence and mood swings, physical symptoms such as bloating and breast pain, and behavioural symptoms such as reduced concentration and aggression.

The NHS lists the most common symptoms as mood swings, feeling depressed or irritable, feeling upset, anxious or emotional, tiredness or trouble sleeping, bloating or cramping, breast tenderness, headaches, spotty skin, greasy hair, and changes in appetite or food cravings. Few people have all of them, and the mix often stays broadly similar from cycle to cycle.

Because many of these symptoms are not specific to hormones, timing is the key. Low mood that lasts the whole month, bloating that never settles, or tiredness that is constant are less typical of PMS and deserve a wider look. The diary described below exists precisely to separate these patterns.

• Emotional: mood swings, irritability, tearfulness, anxiety, feeling overwhelmed.

• Physical: bloating, breast tenderness, headaches, aches and cramping.

• Sleep and energy: tiredness, disturbed sleep, difficulty concentrating.

• Appetite: cravings or increased appetite in the days before bleeding.

The NHS says it is not fully understood why women get PMS, but it may be because of changes in hormone levels during the menstrual cycle, and that some women are more affected by these changes than others. The picture is generally thought to involve sensitivity to normal hormonal fluctuation rather than abnormal hormone levels. That is why blood tests for oestrogen or progesterone are not usually part of the assessment for PMS.

NICE Clinical Knowledge Summaries add a point that guides diagnosis: symptoms must not be better explained by other conditions, and the guidance gives depression, hypothyroidism, anaemia, irritable bowel syndrome and endometriosis as examples. A condition such as depression can worsen before a period without being PMS, so the diary should show a symptom-free week, not simply a worse week.

The NHS recommends keeping a diary of symptoms for at least two menstrual cycles and taking it to a GP appointment. NICE Clinical Knowledge Summaries ask for a daily record for two or three cycles, and say the diagnosis should be confirmed if the diary shows symptoms concentrated in the luteal phase that resolve with menstruation or soon after, followed by a symptom-free week, if they are severe enough to affect work, school or relationships, and if other conditions have been excluded.

A good diary records the date, the day of the cycle, each symptom and a simple severity score, plus anything that affected the day such as poor sleep, illness or stress. It is just as useful for showing what is not PMS as for confirming what is. A GP will also take a history and examine as appropriate to age.

The NHS suggests regular exercise, a healthy balanced diet (some people find smaller meals every two to three hours help), plenty of sleep, reducing stress with approaches such as yoga or meditation, and painkillers such as ibuprofen or paracetamol for pain. It advises against smoking and drinking too much alcohol. NICE Clinical Knowledge Summaries make lifestyle advice and an NSAID for pain the baseline offer to everyone with PMS.

On supplements, the NHS is candid: complementary therapies and dietary supplements such as vitamin B6, calcium, vitamin D and magnesium may help, but there is not much evidence that they work, and acupuncture and reflexology are in the same position. It asks people already taking medicines to check with a GP or pharmacist before starting supplements regularly.

The NHS says a GP may recommend hormonal medicine such as the combined contraceptive pill, cognitive behavioural therapy or antidepressants, and that referral to a gynaecologist, psychiatrist or counsellor can follow if symptoms continue. NICE Clinical Knowledge Summaries name a drospirenone-containing combined pill, CBT and a selective serotonin reuptake inhibitor as options, the last particularly where symptoms are severe or mood-related, and some uses are off-label.

Treatment is tailored to the severity and type of symptoms, the person's preferences and any plans to become pregnant. Response is reviewed after about two months. If primary care treatment does not control symptoms, referral to a clinic with a specific interest in PMS, or to general gynaecology, is considered.