Premenstrual Syndrome

Also known as: PMS

Cyclical physical and psychological symptoms occurring in the luteal phase (typically 1-2 weeks before menses), resolving with/shortly after menstruation onset, with a symptom-free follicular phase ; attributed to normal hormonal fluctuation interacting with individual neurotransmitter (serotonin) sensitivity rather than abnormal hormone levels per se.

Premenstrual dysphoric disorder (PMDD) represents the severe end of the spectrum with predominant, significantly impairing mood symptoms.

Physical: bloating, breast tenderness/swelling, headache, fatigue, joint/muscle aches, appetite changes/food cravings, sleep disturbance.

Psychological: irritability, mood swings, anxiety, low mood, difficulty concentrating, social withdrawal, tearfulness.

Key diagnostic feature: cyclical pattern with symptom-free interval in the follicular phase (distinguishes from other mood/anxiety disorders that are non-cyclical); symptom diary over ≥2 cycles is the diagnostic tool of choice.

Clinical, based on prospective symptom diary (retrospective recall is unreliable) over minimum 2 menstrual cycles confirming the cyclical luteal-phase pattern with follicular-phase resolution.

No specific laboratory test confirms PMS (hormone levels are typically normal).

Exclude other conditions: TSH (thyroid dysfunction can mimic/exacerbate), screen for underlying depression/anxiety disorder (which may be exacerbated premenstrually rather than being pure PMS; "premenstrual exacerbation").

Differentials: underlying mood/anxiety disorder with premenstrual exacerbation, perimenopause, thyroid dysfunction, PMDD (more severe, predominant mood symptoms meeting specific DSM-5 criteria).

Lifestyle: regular exercise, adequate sleep, reduce caffeine/alcohol/salt intake (bloating), regular balanced meals, stress management
Calcium 1200mg/day and vitamin D: modest evidence for symptom reduction
Cognitive behavioral therapy: good evidence, particularly for psychological symptoms
Combined oral contraceptive (particularly drospirenone-containing, continuous/extended cycle regimens): reduces symptoms by suppressing ovulation
SSRIs: effective for significant psychological symptoms/PMDD; can be used continuously OR luteal-phase-only dosing (started ~14 days before expected menses, stopped with menses onset); sertraline, fluoxetine, citalopram
NSAIDs: symptomatic relief for physical symptoms (headache, cramping, aches)
Diuretics (spironolactone): for significant bloating/fluid retention if lifestyle measures insufficient
Severe refractory PMDD: GnRH agonist with add-back HRT (specialist-initiated, induces temporary menopause), or in extreme refractory cases with completed family, surgical options (bilateral oophorectomy) considered; significant/irreversible interventions requiring specialist input

Referral: gynecology/psychiatry for PMDD diagnosis confirmation and severe refractory disease, particularly if considering GnRH agonist or surgical management.

Clinical toolsCalculators

BMI GCS EDD Parkland Formula

Corrected Sodium Corrected Calcium Anion Gap Creatinine Clearance Insulin Calculations qSOFA Wells PE Wells DVT CHA₂DS₂-VASc HAS-BLED CURB-65 Centor/McIsaac

Dysmenorrhoea

Dysmenorrhoea is painful menstruation, classified as primary (no identifiable underlying pelvic pathology, driven by excess endometrial prostaglandin production causing myometrial contraction and ischemia, typically beginning within 1 to 2 years of menarche once ovulatory cycles are established) or secondary (attributable to an underlying condition, most commonly endometriosis, adenomyosis, or fibroids, typically with onset later in reproductive life or a change in a previously established pain pattern).

Primary dysmenorrhoea: crampy, suprapubic pain beginning shortly before or with the onset of menses, lasting 1 to 3 days, often with associated nausea, fatigue, and low back pain, with a normal pelvic examination.

Secondary dysmenorrhoea: pain that may begin earlier in the cycle, persist beyond menstruation, worsen progressively over time, or be associated with other features (deep dyspareunia, abnormal bleeding, subfertility) pointing toward an underlying cause such as endometriosis (see that entry).

Primarily clinical, based on history and a normal pelvic examination for primary dysmenorrhoea.

Red flags prompting investigation for secondary causes: onset after age 25, pain not responding to standard first-line treatment, abnormal bleeding, deep dyspareunia, or an abnormal pelvic examination finding (fixed retroverted uterus, tenderness, or a palpable mass).

Pelvic ultrasound is the first-line investigation where secondary dysmenorrhoea is suspected; laparoscopy remains the gold standard for diagnosing endometriosis specifically (see that entry).

NSAIDs are first line, working directly on the prostaglandin mediated mechanism: mefenamic acid 500 mg PO tds, or ibuprofen 400 mg PO tds to qds, or naproxen 500 mg PO loading dose then 250 mg PO tds, started at or just before the onset of menses and continued for the first 2 to 3 days, generally more effective than paracetamol given the specific prostaglandin mediated mechanism
Hormonal treatment where NSAIDs are insufficient, contraception is also desired, or as an alternative first-line option: combined oral contraceptive (cyclical or continuous/extended regimens, the latter reducing the frequency of withdrawal bleeds and associated pain), the levonorgestrel-releasing IUD, or the progestogen-only pill/injection
Heat application (heat pads) has modest supporting evidence as a low-risk adjunct
Secondary dysmenorrhoea is managed according to the underlying cause identified (see Endometriosis, Uterine Fibroids entries)

Referral: gynecology for suspected secondary dysmenorrhoea, red flag features, or primary dysmenorrhoea not responding to first-line NSAID and hormonal measures.

Premenstrual Syndrome

Overview

Clinical Features

Diagnosis

Management

Overview

Clinical Features

Diagnosis

Management