This narrative review explores the multifactorial pathophysiology of hypertension in peritoneal dialysis (PD) patients, including extracellular fluid overload, sodium and water imbalance, sympathetic overactivity, activation of the renin-angiotensin-aldosterone system (RAAS), loss of residual kidney function (RKF), and inflammation with endothelial dysfunction. The gene discussed is REN; the disease is Hypertension.