Possible causes
- Sensitivity to hormonal changes – it is not about "bad hormones" but a stronger brain response to their fall.
- Serotonin – hormonal shifts affect serotonin, which regulates mood and cravings.
- Stress and lack of sleep – amplify irritability, anxiety and sensitivity.
- Blood sugar swings – sugar cravings and energy crashes worsen mood.
- Nutrient deficiencies – low magnesium, vitamin D or iron may contribute to symptoms.
- Conditions – thyroid disorders or depression often get worse before menstruation.
What to check
- Symptom calendar – record mood and symptoms for 2–3 cycles; it helps distinguish PMS from other problems.
- TSH, ferritin and vitamin D – common and easily addressed deficiencies.
- Progesterone and estradiol – in the right phase of the cycle, as advised by your doctor.
- Prolactin – if you also have tender breasts, an irregular cycle or nipple discharge.
What helps
- Regular exercise – aerobic activity and strength work throughout the cycle ease symptoms.
- Stable eating – protein, fibre and regular meals instead of sweets.
- Less caffeine and alcohol – especially in the week before your period.
- Sleep and rest – plan a less demanding schedule before your period.
- Sensible supplements – magnesium or vitamin B6 are often tried; discuss the choice with your doctor.
When to see a doctor
See a doctor if before your period you experience deep sadness, hopelessness, severe anxiety or anger that disrupt relationships and work, if you have thoughts of self-harm, or if symptoms don't improve after your period. If you have thoughts of self-harm, seek help immediately.