Microalbuminuria is the presence of trace amounts of albumin in the urine. Albumin is one of the important plasma proteins and is called urinary microalbumin because of its low concentration in the urine of healthy people, no more than 20 mg per liter of urine albumin.
When the kidneys and ureters become impaired they leak excess protein into proteinuria. Increased urinary microalbumin is most often seen in diabetes, kidney disease, hypertension, and other diseases. When glomerular and tubular lesions occur, such as nephritis and renal arteriosclerosis, they cause damage to the intrinsic cells of the kidneys, causing changes in cell structure, and proteinuria can occur. Bacterial infectious diseases such as pyelonephritis, renal tuberculosis and sepsis can also cause proteinuria. Other diseases such as kidney stones, polycystic kidney, severe muscle damage, fever, jaundice, hyperthyroidism, hemolytic anemia and leukemia can also cause proteinuria. In addition, increased urinary microalbumin also indicates inflammation in the body, such as urinary tract infections and acute pancreatitis.
Physiological proteinuria can occur after a high-protein diet, during emotional stress, after strenuous exercise, after prolonged exposure to cold, when a woman is pregnant, or when she takes medications that affect kidney function.