The normal range of serum albumin is 40-55 g/L in adults, and more than 55 g/L is an increase in serum albumin. Serum albumin is mainly produced by the liver and is very important for maintaining the body’s colloid osmotic pressure, immune status, and the transport of metabolic substances. The most common cause of increased serum albumin is a relative increase in serum albumin due to blood concentration, but the total amount of serum albumin does not increase significantly. Common causes of increased serum albumin include severe dehydration, such as severe vomiting, diarrhea and insufficient water intake after profuse sweating, certain patients in shock, and hyperalgesia. After rehydration and correction of shock, the albumin concentration will gradually decrease to normal. In clinical practice, increased serum albumin is very rare and is mostly seen in decreased serum albumin, which can be seen in diseases such as severe liver impairment, malnutrition, and chronic wasting.