Why do I get growing-pain-like aches as an adult?

Aching legs in the evening that feel like childhood growing pains have adult explanations, since growth plates closed years ago. The closest match is muscle overuse - a big walking, standing, or workout day bills you that evening with deep, diffuse, both-leg aching that settles with rest, stretching, and warmth. The other fits: vitamin D and magnesium shortfalls, which produce exactly this vague deep ache and are worth testing if aches persist; restless legs syndrome, where the ache comes with an irresistible urge to move and hits at rest in the evening; dehydration and electrolyte dips after sweaty days; and fibromyalgia's diffuse aching, usually with tender points and unrefreshing sleep. The home trial: two weeks of hydration, an evening stretch routine, magnesium-rich food - nuts, leafy greens, legumes - and noting whether aches follow activity. That pattern of trial answers most cases. The flags: aches that are one-sided or localized to one spot, aches with visible swelling, redness, or warmth - one swollen warm calf is the clot emergency - aches with fever, aches that wake you from sleep night after night, or aches with progressive weakness. Bone pain that is deep, constant, and night-waking always deserves a provider visit, per standard bone-pain guidance. Everyday both-leg evening aches after big days: stretch, hydrate, and let them be. Pymander is a free AI doctor, 24/7 by text. Describe where the aches sit and when they come, and it can help you read them.