This book focuses on the study of parasites that affect human health, exploring their biology, life cycles, and impact on hosts. It covers protozoan, helminthic, and arthropod parasites, with an emphasis on epidemiology, pathogenesis, diagnosis, and treatment. The text includes clinical case studies, diagnostic methods, and strategies for prevention and control. Emphasis is placed on understanding the interactions between parasites and hosts, and the implications for public health and clinical practice.