What Causes Red Spots On My Wrist?

I notice when I'm not feeling well a small red spot appears on my left wrist(underside.) It always dissappears, but this morning I had three ring shaped red spots, two connected, one alone. They are under the surface of the skin, not external and they don't itch. They have now faded leaving a very faint pink where they were. Is there a relation between these spots and a viral, fungal, or some other disease or circulatory problem?