This case study summarizes the medical details of 75-year-old male patient Sergio Abbago who was admitted to the hospital due to difficulty breathing and leg swelling. He was diagnosed with atrial septal defect, hospital-acquired pneumonia, and acute urinary retention. The case study provides background on the patient's medical history, presents results from diagnostic testing, discusses the conditions diagnosed and their pathophysiology, outlines the medical and nursing management of the patient, and establishes goals for his care and discharge plan. The objectives are to comprehensively present the case and develop knowledge and skills for delivering quality healthcare to patients.