Premenstrual syndrome is a collection of physical, psychological, and emotional symptoms related to a woman's menstrual cycle.Medical definitions of PMS are limited to a consistent pattern of emotional and physical symptoms occurring only during the luteal phase of the menstrual cycle that are of sufficient severity to interfere with some aspects of life.These symptoms are usually predictable and occur regularly during the ten days prior to menses. Generally, symptoms may vanish either shortly before or after the start of menstrual flow.
Symptoms that have been associated with PMS, but the three most prominent symptoms are irritability, tension, and dysphoria.Common emotional and non-specific symptoms include stress, anxiety, difficulty in falling asleep (insomnia), headache, fatigue, mood swings, increased emotional sensitivity, and changes in libido.Most formal definitions require the presence of emotional symptoms as the chief complaint; the presence of exclusively physical symptoms associated with the menstrual cycle, such as bloating, abdominal cramps, constipation, swelling or tenderness in the breasts, cyclic acne, and joint or muscle pain, is not considered PMS.
The exact causes of PMS are not fully understood.Genetic factors also seem to play a role, as the concordance rate is two times higher in monozygotic twins than in dizygotic twins.Preliminary studies suggest that up to 40% of women with symptoms of PMS have a significant decline in their circulating serum levels of beta-endorphin.
Many treatments have been suggested for PMS, including diet or lifestyle changes, and other supportive means. Medical interventions are primarily concerned with hormonal intervention and use of selective serotonin reuptake inhibitors (SSRIs).Treatment for specific symptoms is usually effective at controlling the symptoms. Even without treatment, symptoms tend to decrease in perimenopausal women, and disappear at menopause.