Parasitic worms are organisms that live inside or on a host, taking nutrients from it to survive. These worms can be found in various environments and can infect animals and humans. Common types include tapeworms, roundworms, and flukes. They often cause health problems, such as digestive issues and malnutrition, by stealing the host's nutrients. Infections from parasitic worms can occur through contaminated food, water, or soil. Prevention includes practicing good hygiene, cooking food thoroughly, and avoiding contact with contaminated sources. Treatment usually involves medication that helps eliminate the worms from the body, allowing the host to recover and regain health.