Filarial worms are parasitic roundworms belonging to the family Filariidae. They are transmitted to humans through the bites of infected mosquitoes or other arthropods. These worms can cause various diseases, including lymphatic filariasis, which leads to severe swelling and disability, and onchocerciasis, also known as river blindness. The life cycle of filarial worms involves multiple stages, including larvae that develop in the host's bloodstream. Once inside the human body, they can live for many years, causing chronic health issues. Effective treatments and preventive measures, such as ivermectin and mosquito control, are essential to manage and reduce the impact of these infections.