Maybe you or someone in your family has visited an allergist. These in-demand doctors treat anyone who's being driven nuts by sneezing, watery eyes, rashes, or scarier reactions like throat swelling. Allergists perform physical exams and administer special skin tests that can determine almost immediately what will trigger a patient's allergic reactions. This knowledge alone can be game-changing for someone who's finally learned that she needs to stop drinking milk or steer clear of cats. Allergists also decide what (if any) medications are needed, and can even prescribe special treatments such as immunotherapy, which helps desensitize a patient from an allergen by exposing them to it in small doses. As an allergist, you'll improve people's lives by not only making them physically breathe easier, but also by making them feel calmer and more in control over their health.