Your rings are tight. Your ankles swell by evening. Your abdomen looks distended even when you've barely eaten. Perimenopause bloating and water retention aren't about eating too much salt — they're about your hormones rewriting the RAAS system that controls how your kidneys handle fluid. Declining progesterone removes your body's natural diuretic brake. Erratic estrogen spikes activate sodium retention. Here's the mechanism, the evidence, and what actually helps.