A urine specific gravity test compares the density of urine with the density of water. It allows doctors to see the concentration of all particles that are present in the urine. A urine specific gravity test gives information about how well the kidneys concentrate the urine and a person's hydration status. The primary function of the kidneys is to maintain a healthy fluid and electrolyte balance. The kidneys excrete excess water and minerals from the body in the form of urine. When the body needs more water, the kidneys retain fluid.

Conditions that cause low specific gravity include:

  • diabetes insipidus

  • kidney failure

  • drinking too much fluid due to increased thirst

  • damage to kidney tubular cells


High specific gravity suggests that the urine is too concentrated.

Conditions that cause high specific gravity include:


Excess substances in the urine can also cause high specific gravity.

Substances include:

  • glucose

  • proteins

  • red or white blood cells

  • bacteria


How to lower specific gravity

If a person has high specific gravity due to dehydration, then the doctor will probably advise them to drink more fluids.

If a person is severely dehydrated or unable to drink, doctors can provide intravenous fluids