PMDD vs ordinary PMS
Most people have some PMS - mild irritability, bloating, tender breasts. PMDD is different in severity: marked depression, anxiety, anger, or hopelessness that significantly impairs your life. Up to ~5-8% of menstruating people have PMDD.
Symptoms and timing
Symptoms appear in the luteal phase (after ovulation, the 1-2 weeks before your period) and lift within a few days of bleeding starting. Key signs: severe mood swings, depression or hopelessness, anxiety or tension, irritability or anger, feeling overwhelmed, loss of interest, trouble concentrating, plus physical PMS symptoms.
Why it happens
PMDD isn't a hormone imbalance - hormone levels are normal. It's an abnormal sensitivity of the brain to normal cyclical changes in progesterone and its metabolites, affecting serotonin. That's why it follows the cycle so precisely.
How it's diagnosed
By tracking symptoms daily for at least 2 cycles - showing they cluster in the luteal phase and resolve after your period. A symptom diary (like the one in Luna) is the single most useful tool to bring to your doctor.
What helps
Effective options include SSRIs (antidepressants, sometimes taken only in the luteal phase), certain combined birth control pills, CBT, and lifestyle support (exercise, sleep, reducing alcohol/caffeine). Calcium and other supplements may help milder cases. A doctor can tailor treatment - you don't have to just endure it.