Worm infestation occurs when parasitic worms invade the body, often affecting the intestines. Common types include roundworms, tapeworms, and hookworms. These worms can enter the body through contaminated food, water, or soil, leading to various health issues such as abdominal pain, diarrhea, and weight loss. Diagnosis typically involves stool tests to identify the presence of worms or their eggs. Treatment usually includes medications that kill the parasites. Preventive measures include practicing good hygiene, washing hands regularly, and ensuring food is properly cooked to reduce the risk of infection.