What Causes Sudden Shooting Pain And Swelling In Thumb?

hi. My question deals with sudden shooting pain in my right thumb. When i touch the base of the thumb, on the palm side, right where the webbing attaches and push towards the bon, the pain starts. Gripping the steering wheel, changing the sheets on the bed (running the fabric through the notch between thumb and forefinger), or just lightly touching the pain point sends pins and needles sharp pain through the thumb and hand. It might be a bit swollen right at the base of the thumb over the pain spot. I don't recall any injury to the area, just noticed the pain when it was touched. What might be causing this and what should I do to bring about relief?