Isosthenuria
Encyclopedia
Isosthenuria refers to the excretion of urine whose specific gravity
(concentration) is neither greater (more concentrated) nor less (more dilute) than that of protein-free plasma
, typically 1.008-1.012.
A closely related term is hyposthenuria, where the urine has a relatively low specific gravity, though not necessarily equal to that of plasma. Therefore, unlike isosthenuria, this condition is not associated with renal failure as the kidney tubules have altered the glomerular filtrate
in which the kidneys lack the ability to concentrate or dilute the urine
and so the initial filtrate of the blood remains unchanged despite the need to conserve or excrete water based on the body's hydration status.
Sickle-cell trait, the heterozygous form of sickle-cell disease
, presents with a normal hematological picture but is associated with isosthenuria and increased frequency of urinary tract infection
s.
Specific gravity (kidney)
Specific gravity, in the context of clinical pathology, is a urinalysis parameter commonly used in the evaluation of kidney function and can aid in the diagnosis of various renal diseases.-Background:...
(concentration) is neither greater (more concentrated) nor less (more dilute) than that of protein-free plasma
Blood plasma
Blood plasma is the straw-colored liquid component of blood in which the blood cells in whole blood are normally suspended. It makes up about 55% of the total blood volume. It is the intravascular fluid part of extracellular fluid...
, typically 1.008-1.012.
A closely related term is hyposthenuria, where the urine has a relatively low specific gravity, though not necessarily equal to that of plasma. Therefore, unlike isosthenuria, this condition is not associated with renal failure as the kidney tubules have altered the glomerular filtrate
Clinical significance
This is the hallmark of such disease states as chronic and acute renal failureRenal failure
Renal failure or kidney failure describes a medical condition in which the kidneys fail to adequately filter toxins and waste products from the blood...
in which the kidneys lack the ability to concentrate or dilute the urine
Urine
Urine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...
and so the initial filtrate of the blood remains unchanged despite the need to conserve or excrete water based on the body's hydration status.
Sickle-cell trait, the heterozygous form of sickle-cell disease
Sickle-cell disease
Sickle-cell disease , or sickle-cell anaemia or drepanocytosis, is an autosomal recessive genetic blood disorder with overdominance, characterized by red blood cells that assume an abnormal, rigid, sickle shape. Sickling decreases the cells' flexibility and results in a risk of various...
, presents with a normal hematological picture but is associated with isosthenuria and increased frequency of urinary tract infection
Urinary tract infection
A urinary tract infection is a bacterial infection that affects any part of the urinary tract. Symptoms include frequent feeling and/or need to urinate, pain during urination, and cloudy urine. The main causal agent is Escherichia coli...
s.