Ascariasis is an infection caused by the roundworm Ascaris lumbricoides. This parasite is commonly found in areas with poor sanitation, where contaminated soil or food can introduce the eggs into the human body. Once ingested, the eggs hatch in the intestines, and the larvae can migrate through the bloodstream to the lungs before returning to the intestines to mature. Symptoms of ascariasis can include abdominal pain, nausea, and diarrhea, but many infected individuals may not show any symptoms. Treatment typically involves antiparasitic medications, which effectively eliminate the worms from the body. Preventive measures include proper hygiene and sanitation practices.