I have throbbing and warmth in the tip of my ring finger. is this infection? there has been no trauma to area or any signs of bites or scratches. just started hurting.

While : While most infections have a so-called "portal of entry, " not all of them do. We don't always understand what causes infections in some people. Pain, redness, and swelling that are progressive should be evaluated immediately, as some infections can cause serious tissue damage or life-threatening illness if not treated promptly. Other causes of pain, throbbing, and warmth at a fingertip include gout, pseudogout, vascular problems, certain benign growths, and trauma. A hand surgeon can help determine the cause and treatment.

It : It can be. Redness, tenderness, swelling, pain, tightness or stiffness with pain also indicate an infection. Just throbbing alone is less likely. Add a few more of these symptoms and then it is more lilkely. As mentioned gout, pseudogout and other things can simulate and infection.