Human Serum Albumin (HSA) is a protein found in human blood plasma. It plays a crucial role in maintaining the osmotic pressure of blood, which helps regulate fluid balance in the body. HSA also serves as a carrier for various substances, including hormones, fatty acids, and drugs, facilitating their transport throughout the bloodstream. Produced primarily in the liver, HSA constitutes about 60% of the total protein in plasma. Its levels can be affected by various conditions, such as liver disease, kidney disorders, and malnutrition. Due to its importance, HSA is often used in medical treatments, including fluid replacement therapies.