I’ve been having this a lot the last few months. I’m not sure if it’s diabetes related or not. I just had one a short time ago after a nap. The leg ones are bad but they are easier to deal with because you can sort of walk them off or stretch your leg in the right way to get them to go away. The ones I get in my sides are a pain because you have to move into awkward positions and stay there for extended periods of time to get them to go away.
I get them in the legs. If I complain my sister starts listing off foods rich in potassium, always with banana on top. Eat a banana she tells me. I do. It works.
My first thought was vitamin deficiency, like k, d or folic acid. You should be taking a multi vitamin anyway. At your elderly age. but definitely drink more water and have your doctor check.