What Causes Cramping And Locking Of Fingers?

I am a 74yo fand at different times my hands/fingers will cramp. There are times when the first two fingers will lock and I have to pull them apart.I get some relief using Sports creme but don't understand what is causing this.Like today I was just reading and holding the news paper.The creme helps but my hands feel really tight,sometimes the cramping /locking involves my wrist also.If I put them in really warm waterit also helps,other than this I am considered to be in Great health ,