The Eisenmenger Complex, also known as Eisenmenger Syndrome, is a rare medical condition characterized by a combination of heart defects and pulmonary hypertension. Synonyms for Eisenmenger Complex include Eisenmenger Pathology, Eisenmenger Reaction, and Congenital Heart Disease with Pulmonary Hypertension. These terms describe the same condition, highlighting the abnormal blood flow and increased pressure in the arteries of the lungs, leading to complications such as cyanosis, heart failure, and decreased exercise capacity. While the name may differ, the underlying mechanism and clinical implications remain the same. Prompt diagnosis and appropriate management are crucial in improving the prognosis for patients with Eisenmenger Complex.