This kind of sensation is sometimes experienced, a bit like growing pains in reverse! The body becomes more prone to aches and pains as oestrogen levels fall. However, it’s always sensible to get these things checked out by the doctor too.
I’d suggest some magnesium (e.g. Salus Haus liquid magnesium, which also tastes nice!) and staying mobile – maybe some gentle yoga to keep the circulation flowing. If you smoke then obviously it would be sensible to cut down with a view to giving up, as it affects circulation.