Infectious diseases remain a major global health challenge, particularly in developing countries. Diagnosis often relies on a combination of clinical features, laboratory tests, imaging, and sometimes molecular techniques. Treatment depends on the causative agent and may include antibiotics, antivirals, antifungals, or antiparasitic medications. Preventive measures such as vaccination, hygiene, safe food and water, and vector control are crucial to reduce the incidence of these diseases. Emerging infectious diseases and antimicrobial resistance pose ongoing challenges in their control and management.