Low blood protein levels can be caused by liver, kidney and intestinal diseases. A condition known as nephrotic syndrome — characterized by high cholesterol and excess protein in the urine — might also lead to low protein levels. Malnutrition is an additional cause of low protein levels in the blood.
In patients with liver disease the capacity to break down and synthesize protein is impaired. Excessive drinking of alcohol and scarring of the liver tissue can contribute to the development of liver disease. One of the main functions of the liver is to produce enough protein to support the immune system. If it is unable to produce enough, low blood protein levels can be a result.
Malfunctions in the kidneys can also lead to low protein levels. Under normal conditions, the kidneys help keep the blood clean of unnecessary acids and minerals and will cause the body to secrete these wastes. When kidneys become infected, they can leak excess protein into urine instead of maintaining it in the body's bloodstream. Some kidney diseases are the result of other conditions such as diabetes.
Low protein levels might also be caused by disorders of the intestinal tract. There are certain conditions and allergic reactions that may prevent proteins from becoming absorbed by the intestines. If proteins are not properly absorbed and synthesized, they are released by the body as waste. This prevents the bloodstream from accumulating and maintaining the proper levels.
Malnutrition is another leading cause of low protein levels. Individuals who are not consuming enough through their diets are at risk. Pregnancy is another risk factor for developing low protein levels since the added stress of fetal development requires an increased protein intake.
Those with certain disorders, such as immune deficiency, can experience low levels of protein. Some of these immune disorders are genetic and some are acquired. Immune disorders can cause the body to attack cells and nutrients that are beneficial, including protein.
Nephrotic syndrome usually results in a combination of generalized swelling and inflammation, high cholesterol, excess protein in the urine and low protein levels. Poor hygiene habits might lead to a low blood protein since harmful organisms can invade a person's system through vulnerable openings such as the eyes and the nose. The body needs additional protein broken down in order to fight off infections and invading organisms. This would most likely result in a short-term reduction in the body's overall protein levels.