I Have A Hard Knot On The Inside Of My

I have a hard knot on the inside of my right arm. Closer to the elbow but not in my crease it's relatively small looks like the size of a bee sting when it is swells. And another on my left arm by my elbow but it's almost like my elbow is swollen by the crease but closer to the elbow it's literally on the fold of my arm. It's not a lump but it looks swollen and seems tight