Leprosy is a chronic disease that affects the skin, nerves, and mucous membranes. Lepromatous leprosy is the most severe form of the disease, causing extensive damage to tissues and organs. There are several synonyms for lepromatous leprosy, including multibacillary leprosy, diffuse leprosy, and borderline lepromatous leprosy. Multibacillary leprosy refers to the presence of multiple bacterial organisms in the skin, while diffuse leprosy describes the spread of the disease throughout the body. Borderline lepromatous leprosy is a subtype of the disease that falls between lepromatous and borderline tuberculoid leprosy. Regardless of name, early detection and treatment are crucial to slowing the progression of lepromatous leprosy and preventing complications.