Low prealbumin is usually caused by kidney disease, liver disease, inflammation, malnutrition and other diseases. 1. Kidney disease: such as membranous nephropathy, which can cause low albumin and prealbumin levels in the body due to excessive protein excreted in the urine. 2. Liver disease: such as hepatitis B, cirrhosis, hepatocellular carcinoma and other liver diseases, which can lead to liver cell damage, and the main synthesis place of prealbumin is the liver, so it will make the amount of prealbumin lower. 3. Inflammation: when acute inflammation occurs in the body, it can cause tissue damage at the site of inflammation, which requires a large amount of protein to participate in tissue repair, thus leading to a decrease in prealbumin in the body. 4. Malnutrition: when eating too little, or supplemental nutrition is not comprehensive, the lack of protein in the food, will make the body lack of raw materials to synthesize proteins, thus reducing the level of pre-albumin. When prealbumin decreases, the cause of the disease should be identified and treated in a timely manner.