When serum glucose spills into the urine – this is termed glucosuria. Typically, glucose in urine does not occur until the kidney glucose threshold is reached – which is around 180mg/dL. As you can tell, this can be useful for evaluating hyperglycemia in the setting of diabetes. However, periods of stress or fever have been known to cause small amounts of glucose within the urine as well, so glucose in urine does not automatically mean diabetes

• Glucosuria can indicate hyperglycemia in undiagnosed diabetics when blood work is not obtained.
• Fever or stress could cause mild glucosuria in non-diabetics
• SGLT2 inhibitors like Farxiga can increase glucose in urine even without elevated glucose levels

Urinary bilirubin may be present in low amounts in the urine normally, but increased levels are due to abnormalities of bilirubin metabolism or liver function.

• The presence of bilirubin may indicate elevated LFTs, but overall does not seem to add significant information toward diagnosis.

Normal Levels: None ( 0.3 mg/dL or  0.05 mmol/L)

The presence of ketones in the urine (ketonuria) indicates ketosis. This is usually caused by uncontrolled diabetes or DKA. However, acute illness, stress on the body, strenuous exercise, nausea/vomiting, and keto or other low-carb diets can cause ketonuria to occur. 

Normally ascorbic acid is not seen in the urine dipstick.

Ascorbid acid is Vitamin C. The presence of this in the urine can lead to false negatives for both Heme, glucose, leukocyte esterase, and protein.

The specific gravity indicates how dilute or concentrated the urine is. This can give the interpreter a pretty good idea of hydration status when looking at the urinalysis.

Normal Levels: 1.005 – 1.030

Low (<1.005): May indicate diabetes insipidus, renal failure, pyelonephritis, glomerulonephritis, psychogenic polydipsia, or malignant hypertension

High (>1.030): May indicate severe dehydration, hepatorenal syndrome, heart failure, renal artery stenosis, shock, or SIADH.

Heme detects blood in the urine.

There are many potential causes of hematuria including UTIs, kidney/glomerular damage, trauma, kidney stones, malignancy, vaginal contamination, or coagulopathies.

In a patient over 50 years old who has persistent hematuria, malignancy should be ruled out. 

Normal Levels: Negative

The test for heme is very sensitive and can detect down to 1-2 RBCs per High-powered field (HPF). So a negative dipstick excludes blood.

The pH of urine stands for the potential of hydrogen. The more hydrogen ions there are, the more acidic something is.

The pH scale runs of 0-14, with lower numbers being more acidic, and higher numbers being more basic.

Because the kidneys regulate your acid/base balance, any change within the body should show up in your urine. However, various different disease processes can interfere with your kidney’s ability to do this effectively.

Normal Levels: 6, but can range from 4.6 – 8

Acidic urine <7.0 is associated with metabolic or respiratory acidosis or an E Coli UTI.

Basic urine >7.0 is associated with most types of kidney stones, urea-splitting bacteria (proteus or klebsiella), renal tubular acidosis, or potassium depletion.

The urine protein dipstick is specific for albumin, which is a type of protein. Any damage to the glomerular basement membrane will let albumin and other larger particles pass through the membrane and into the urine.

Protein in urine is typically used to evaluate kidney damage in diabetics, people with Congestive Heart Failure (CHF), or other causes of kidney damage.

Benign causes of high protein in urine include dehydration, emotional stress, fever, heat injury, inflammation, intense activity, acute illness, or an orthostatic disorder.

All other causes of proteinuria involve the kidney – specifically the glomerulus or the renal tubules. Some common causes of glomerular proteinuria include Diabetic nephropathy, lupus nephritis, preeclampsia, various infections (HIV, hepatitis B, post-streptococcal glomerulonephritis), certain cancers, and certain drugs like Heroin, NSAIDs, and Lithium. Some causes of tubular proteinuria include interstitial cystitis, Sickle-cell, and nephrotoxicity from NSAIDs or antibiotics like aminoglycosides.

Normal Levels: Undetectable

The urine normally has <150mg/day of protein and should be undetectable on a dipstick, but when this level exceeds 300mg/day, high protein in urine will show up on a dipstick.

Urobilinogen is a byproduct of bilirubin production, but unlike bilirubin is colorless.

Elevated levels can indicate malaria, hemolytic anemia, liver disease, or internal bleeding.

An increased urobilinogen level is one of the earliest signs of liver disease and hemolytic disorders.

Normal Levels: 0.1–1 Ehrlich U/dL or 1 mg/dL

Nitrates are present in the urine at baseline. Some species of bacteria, specifically the Enterobacteriaceae species (E. coli, Klebsiella, Proteus, Enterobacter, Citrobacter, and Pseudomonas), release an enzyme called nitrate reductase which converts urinary nitrate to nitrite, causing nitrites in urine.

If negative, it really doesn’t mean much. If positive, then it is highly likely an infection is present.

Normal Levels: Negative

Leukocyte esterase is a component of WBCs that is released when these white blood cells are lysed (split open).

The presence of leukocyte esterase supports the diagnosis of a Urinary Tract Infection (UTI). However, the presence can also indicate various autoimmune disorders, STDs, kidney stones, or intra-abdominal infections.

If there is no leukocyte esterase, infection is pretty much ruled out.

Normal Levels: Negative