Specific gravity

All information on specific gravity

At a glance

The specific weight of the urine, also called specific gravity, indicates the concentration of the urine.

If the urine is very concentrated, probably too little was drunk and the specific. gravity is increasing. Also large loss of fluid due to heavy sweating or diarrhoea leads to a higher specific density of the urine. When drinking is high, the urine is diluted and the specific gravity decreases.

For the maintenance of the fluid and electrolyte balance (homeostasis) in the body, the ability to concentrate and dilute the kidneys is crucial. This can be determined by the specific gravity of the urine.

However, the specific gravity of the urine is also important for the interpretation of other measurements in the urine, such as protein, blood, nitrite, glucose and leukocytes. It should be taken into account in order to avoid misinterpretation due to excessive or low urine concentration.

For more information

In addition, it can be determined whether a urinalysis should be intentionally falsified. Due to extremely high drinking amounts and thus dilution of the urine, e.g. in doping tests in the sports field or also during drug tests, attempts are made to influence the results again and again.

The normal specific weight of the urine varies between 1,001g/ml and approximately 1.04 g/ml.

If the value deviates upwards or downwards during a single measurement, this is not necessarily an indication of a disease, since the density depends strongly on the fluid intake.

Depending on the measurement method, protein, sugar, blood, X-ray contrast agents or infusions can increase the specific weight of the urine.

Sources

  • Hübl, W.: Dichte / Spezifisches Gewicht des Harns – Übersicht, URL: https://www.med4you.at/laborbefunde/lbef3/lbef_spezifisches_gewicht_harn.htm, Retrieved 18.06.2019
  • Antwerpes, F.: Spezifisches Uringewicht, URL: https://flexikon.doccheck.com/de/Spezifisches_Uringewicht, Retrieved 18.06.2019
  • Lahnsteiner, E. et al. (2004): Harnanalyse – praktisch zusammengefasst, 2. Auflage
Status of information: Autumn 2019