Medical specialists are doctors that have completed advanced education and clinical training in a specific area of study. They can be addiction specialists, anesthesiologists, and dermatologists. Most medical specialists only perform very specialized diagnostics to determine the issues that are causing illness or other problems. There are internal specialists, specialists that deal with specific age ranges (like pediatricians), diagnostic or therapeutic specialists, and technique or organ-based specialists. Get more information on the types of specialists and what they do.