Plasmodium falciparum is a single-celled parasite that causes the most severe form of malaria in humans. It is transmitted through the bite of infected Anopheles mosquitoes. Once inside the human body, the parasite multiplies in the liver and then infects red blood cells, leading to symptoms such as fever, chills, and anemia. This parasite is responsible for the majority of malaria-related deaths worldwide, particularly in tropical and subtropical regions. Effective treatments include antimalarial medications, but resistance to these drugs is a growing concern. Preventive measures, such as using insecticide-treated bed nets, are crucial in controlling its spread.