The Premenstrual Syndrome

Synonyms: PMS, Premenstrual tension, PMT, Premenstrual dysphoria, Late Luteal Phase Dysphoric Disorder (LLPDD)

Premenstrual Syndrome is the cyclical appearance of unpleasant symptoms from sometime in the second week of the menstrual Cycle (luteal phase) to one or two days into the next cycle (after starting menses, the follicular phase).
Sometimes the symptom-free period can be as little as a week long, but there must be at least one week without symptoms, in each cycle, for the symptoms to be attributable to this condition.
PMS is characterised by:

• Psychological symptoms; irritability, labile affect, low mood, anxiety and lassitude.
• Physical symptoms; breast tenderness, bloatedness, clumsiness and fluid retention also occur.¹

Research into the causes of PMS tends to point to an exaggerated response to circulating hormones, rather than an abnormality in their circulating levels.^2,3,4Other proposed aetiologies include nutritional deficiencies in magnesium and calcium,⁵ relative CNS serotonin deficiency, hypoprolactinaemia, endorphin effects⁶ and excessive levels of nitrous oxide.⁷
Pre-existing conditions such as migraine, mastalgia,⁸ depression,⁹ backache, acne and asthma¹⁰ can be worsened cyclically. There is often exacerbation of pre-existing psychiatric or psychological problems.³
There is ongoing debate as to whether premenstrual syndrome actually constitutes an illness, or is better viewed as a cyclical physiological phenomenon. It severely affects the lives of a proportion of its sufferers, who may seek medical help to overcome its symptoms. The risk of psychological illness appears to be higher amongst women who suffer menstrual problems.¹¹

It is estimated that up to 1.5 million women in the UK experience such severe symptoms that their quality of life and interpersonal relationships are greatly affected. About 35% of these women seek medical help.¹² It affects around 85% of women to some extent, at some time in their life; about 10% of women suffer marked life-disruption in their mid-20s to mid-40s.^1,2,13

Risk factors

• Obesity
• Smoking¹⁴
• Poor diet
• Lack of exercise⁶

Symptoms vary between cycles; they tend to be worse about two weeks prior to menses and improve a few days after starting the period.
The main symptoms leading to a consultation are irritability and inability to cope with domestic or workplace demands.

• Physical symptoms usually lead to a consultation only when mastalgia, dysmenorrhoea or migraine have not responded to self-management.
• Difficult interpersonal relationships with spouse or children may also precipitate a consultation.
• Psychosexual problems, loss of libido and dyspareunia may be reported but usually have to be specifically asked about.

NB: Be careful not to unquestioningly accept parent-reported diagnosis of PMS in adolescent girls who may have more serious underlying psychological illness.⁶
There are no specific signs of the syndrome, so problem best delineated on basis of history and symptom diary kept over 2-3 months.
There may be leg or breast oedema.

These include psychological conditions worsened by PMS.¹
Need to consider depression, hyperthyroidism and hypomania.

• Check BP and pulse rate.
• Consider breast and thyroid examination.
• Are the patient's smears up to date? Consider pelvic examination, particularly if bloating is a major problem (?ascites due to alternative ovarian pathology), or other reason to suspect physical cause of tummy swelling.

There are no useful tests to confirm the diagnosis.
Consider TFTs/FBC/ESR/U&E if reason to suspect alternative physical cause for symptoms.

Non-drug

Get the patient to keep a symptom diary to help with diagnosis and assess effectiveness of interventions.
The most important part of the management is to reassure the patient that you understand her concerns and the disruption that symptoms are causing to her life. Quite often the friction caused by their irritability and volatility alienates the patients from usual sources of support at work and home. As PMS can be a long-term problem there are lifestyle changes that may help the patient cope with the symptoms. Reassure that there are many ways to help and it is a matter of finding the best treatment strategy.

• Try regulating carbohydrate intake; complex carbs every 2-3hrs and avoid excess sugar.⁸
• Reduce saturated fats and caffeine; may improve mastalgia. Good diet may correct any subclinical nutrient deficiencies (e.g. Mg, Ca) and improve symptoms.
• Vitamin D and calcium supplementation are being investigated as preventive agents.¹⁵
• Reducing salt intake may reduce fluid retention.
• Use firm, supportive bra day and night.
• Support stockings help aching legs.
• Gentle exercise is effective.¹⁶

Try re-scheduling more stressful tasks to the better half of the month. Get patient to explain PMS to friends and family to improve support. Cognitive Behavioural Therapy may be useful in motivated patients.¹⁶
Relaxation exercises are helpful as are methods of coping with stress such as assertiveness and time management training.
Other remedies such as fennel tea and camomile tea may reduce breast tenderness. They act as a good substitute for tea and coffee, which may aggravate irritability further.

Drugs

Treatment needs to be tailored to the severity of the PMS. Placebo effect can make a difference in up to 90%.
Try simple analgesia as required for breast tenderness, headaches and period pains. Mefenamic acid and naproxen from day 15 to day 2-3 of the next period are effective, but have adverse effects.

• Pyridoxine is reported to help, but there is little definitive evidence.¹⁶
• Diuretics (esp. spironolactone) do improve bloating and swelling but many women with PMS have no objective evidence of fluid retention.
• SSRIs improve symptom scores but there are significant adverse effects and mixed trial results between agents.^16,17
• There may be a subset of women who have a primary mood disorder worsened by menstrual factors - Luteal Phase Dysphoric Disorder.⁹ Light therapy has been shown to help psychological symptoms in this group.¹⁸
• Combined oral contraceptives are generally reported to improve symptoms and have a physiologically plausible mode of action. There is little good trial data to support their use.¹⁶ Tricycling the pill has been shown to reduce frequency of symptoms.¹⁹
• Progesterone should not be used and progestogens are unlikely to help.¹²
• Danazol, bromocriptine for breast symptoms and gonaderelin analogues can be considered if symptoms severe, but any benefits must be traded off against potential adverse effects.
• Mastalgia may be improved by evening primrose oil and has few adverse effects (however, may rarely worsen epilepsy).¹⁶
• Flavonoids (soya is rich in these) may help fluid retention/leg symptoms.^20,21

Surgery

There is no evidence supporting routine use of surgical treatments for PMS. Hysterectomy ±oophorectomy with oestrogen-only HRT should be a last resort and risk/benefit ratio carefully considered. If a severe sufferer is sure that she does not want any more children then it may be an option to consider.

In young women, consider birth control needs as well as PMT. Sometimes both can be met using the combined oral contraceptive pill. Most women can find effective solutions to their symptoms. A small number continue to be severely affected with worsening symptoms, until the menopause.

1) Make a proper assessment before attributing symptoms to PMS, to avoid missing other causes of erratic or dysphoric behaviour.
2) PMS has been considered as a mitigating circumstance in some courts for certain minor criminal offences such as shoplifting.