Esophageal candidiasis is a fungal infection of the esophagus caused by the overgrowth of the Candida species, most commonly Candida albicans. It often occurs in individuals with weakened immune systems, such as those with HIV/AIDS, diabetes, or those undergoing chemotherapy. Symptoms may include difficulty swallowing, pain while swallowing, and chest pain. Diagnosis typically involves an endoscopy, where a doctor examines the esophagus and may take a tissue sample for testing. Treatment usually includes antifungal medications, which can help eliminate the infection and alleviate symptoms. Early detection and treatment are important for effective management.