Urine Specific Gravity (SG)

The specific gravity (SG), which is the urine specific gravity, refers to the ratio of urine to the same volume of pure water at 4 degrees Celsius. Because the urine contains 3-5% solid matter, the urine is longer than pure water. The specific gravity of urine varies with the content of water, salt and organic matter in the urine. In the case of pathology, it is also affected by protein, urine sugar and cell components. For example, the imbalance of anhydrous metabolism, the urine specific gravity can roughly reflect the concentration and dilution function of renal tubules. . This test is suitable for people with kidney disease, dehydration or excess water, and suspected abnormal substance excretion. Basic Information Specialist classification: urinary examination classification: urine / kidney function test Applicable gender: whether men and women apply fasting: fasting Analysis results: Below normal: Mainly seen in chronic glomerulonephritis, pyelonephritis and other diseases that cause serious damage to the distal nephron concentrating function, also seen in renal insufficiency, diabetes insipidus, large amounts of drinking water and fluid replacement. Normal value: Urine specific gravity: 1.002-1.030 Above normal: It can be seen in high fever, excessive sweating, vomiting, diarrhea and other dehydration, insufficient drinking water, acute glomerulonephritis, cardiac insufficiency, peripheral circulatory failure and other urinary oliguria; also seen in urine containing glucose and iodine migration agents. negative: Positive: Tips: Pay attention to the effect of room temperature: for every 3 °C increase in temperature, the specific gravity of urine should be increased by 0.001, and for every 3 °C decrease in temperature, the specific gravity of urine should be reduced by 0.001. Normal value The maximum range is 1.002~1.030, generally 1.015~1.025, and morning urine is about 1.020. Clinical significance 1. Increased urine specific gravity can be seen in high heat, excessive sweating, vomiting, diarrhea, etc. Dehydration, insufficient drinking water, acute glomerulonephritis, cardiac insufficiency, peripheral circulatory failure, etc.; also seen in urine containing glucose and iodine When moving the agent. 2, the reduction of urine specific gravity is more valuable for clinical diagnosis. The urine that is discharged near the ratio of 1.010 (close to the glomerular filtrate) is called isotonic urine, mainly seen in chronic glomerulitis, pyelitis and other distal kidneys. Diseases with severe dysfunction in unit concentration are also seen in renal insufficiency, diabetes insipidus, heavy drinking water and fluid replacement. Urine specific gravity is useful for the identification of two types of polyuria diseases, diabetes and diabetes insipidus. In the case of diabetes insipidus, the amount of urine is extremely large, and the specific gravity is very low, which is almost 1; in the case of diabetes, the urine contains a large amount of glucose, and the specific gravity is increased. Repeated measurement of urine specific gravity for 24 hours helps to understand the concentrated and diluted function of the kidney. Low results may be diseases: pregnancy-induced hypertension, acute glomerulonephritis results may be high disease: kidney dysfunction precautions 1. Pay attention to the influence of room temperature: for every 3 °C increase in temperature, the specific gravity of urine should be increased by 0.001. For every 3 °C decrease in temperature, the specific gravity of urine should be reduced by 0.001. 2. When the urine protein content is high, for every 1% increase, the urine specific gravity should be reduced by 0.003. 3. When the salt crystals are precipitated in the urine, the specific gravity may decrease, and the specific gravity should be measured after the salt is dissolved. 4, check the urine as soon as possible after the urine, so as not to decompose the urea and reduce the proportion. Inspection process After thoroughly mixing the urine, slowly pour it into the small cylinder along the wall of the tube. If there is foam, use a dropper or filter paper to remove it. Then put in the hydrometer, do not let the hydrometer touch the wall or bottom of the glass cylinder. After the hydrometer is stable, read the scale tangent to the concave surface of the urine and report it. Not suitable for the crowd Generally no taboos. Adverse reactions and risks Generally not.