What Causes Soreness And Cramping Pain In Thumb?

ive had a sore cramping pain in my right thumb for 3days,ive just looked at my thumb and can see a vein running up it and that is where the pain is coming from, it is sore to touch and now just above my elbow on my right arm it is also sore like a cramp and below the elbow is starting to feel fuzzy? what could this be?