Most people think of ringworm as a plant, but it's actually not. Ringworm is a type of fungus that can infect the skin, nails, and scalp. It's important to note that ringworm is not caused by worms, and it's not contagious. If you have ringworm, you can treat it with over-the-counter antifungal creams or lotions. In some cases, oral antifungal medications may be necessary.