You’re jolted awake by a vice-like grip in your calf—a muscle seized in a painful knot. You massage it, curse the darkness, and pray it releases before you wake the household. For millions, this isn’t a rare nightmare—it’s a weekly or even nightly reality.

While anyone can suffer nocturnal leg cramps, research reveals five high-risk groups where these spasms aren’t just common—they’re predictable. More importantly, science now shows why they happen and—critically—how to stop them before they strike.

1. Adults Over 60: The Silent Epidemic
The risk: 60%+ of seniors experience weekly night cramps (not 30%—older studies underestimated severity).
Why it happens:

Muscle atrophy: 3–8% muscle mass loss per decade after 30 weakens calf muscles.
Nerve degradation: Slower signals from spinal cord → erratic muscle firing.
Circulation collapse: Nighttime blood flow to legs drops 40% vs. daytime (per Journal of Vascular Medicine).
Red flag: Cramps lasting >10 minutes often signal peripheral artery disease (PAD)—a precursor to heart attack/stroke.