Evidence-Based Supplement & Herb Guides

Sperm in Urine Test: Retrograde Ejaculation, Sample Finding, and Meaning

Sperm in urine can be normal after ejaculation or may suggest retrograde ejaculation in the right setting. Learn causes, post-ejaculatory urine testing, fertility effects, and follow-up.

Sperm can sometimes be seen in urine without indicating disease. After ejaculation, a small amount of semen may remain in the urethra and wash...

Struvite Crystals in Urine: UTI Stones, Alkaline Urine, and Infection Risk

Struvite crystals form in alkaline urine and can be linked to urease-producing UTIs and infection stones. Learn microscopy clues, testing, treatment, recurrence risk, and urgent warning signs.

Struvite crystals in urine are magnesium ammonium phosphate crystals that often form in alkaline urine. Their most important association is with urinary infections caused...

Triple Phosphate Crystals in Urine: Struvite Crystals, UTI, and Alkaline Urine

Triple phosphate crystals are usually struvite and often form in alkaline urine linked to urease-producing UTIs. Learn microscopy clues, stone risk, testing, treatment, and warning signs.

Triple phosphate crystals are usually another name for struvite, a magnesium ammonium phosphate crystal that forms most readily in alkaline urine. On urine microscopy,...

Tyrosine Crystals in Urine: Liver Disease, Metabolic Disorders, and Meaning

Tyrosine crystals in urine are rare and may point to severe liver dysfunction or metabolic disease. Learn their microscopy appearance, causes, confirmation tests, and warning signs.

Tyrosine crystals are a rare and abnormal urine microscopy finding. They usually appear as very fine needles arranged in bundles, sheaves, or rosettes and...

Uric Acid Crystals in Urine: Gout, Kidney Stones, Acidic Urine, and Meaning

Learn what uric acid crystals in urine mean, how acidic urine, gout, dehydration, and kidney stones are connected, and when follow-up or treatment is needed.

Uric acid crystals in urine are most often a sign that the urine is acidic enough for uric acid to come out of solution....

Urine Microscopy for Kidney Disease: Casts, Cells, Crystals, and Sediment Findings

Understand how urine microscopy helps evaluate kidney disease, including red and white blood cells, tubular cells, casts, crystals, sediment patterns, and follow-up.

Urine microscopy can reveal kidney injury that a dipstick or blood test cannot fully explain. After a urine sample is concentrated and examined under...

Urine Microscopy Test: Cells, Casts, Crystals, Bacteria, and Sediment Findings

Learn how a urine microscopy test identifies cells, casts, crystals, bacteria, yeast, and sediment, what common findings mean, and when follow-up is important.

A urine microscopy test examines the solid particles in urine after a sample is collected and prepared for microscopic analysis. It can show red...

Urine Sediment Test: Microscopic Findings, Kidney Disease, Infection, and Meaning

Learn what a urine sediment test shows, including cells, casts, crystals, bacteria, and yeast, and how microscopic findings can point to kidney disease or infection.

A urine sediment test examines the cells, casts, crystals, microorganisms, and other particles that settle out of urine. It is one of the most...

Waxy Casts in Urine: Chronic Kidney Disease and Advanced Kidney Damage

Learn what waxy casts in urine mean, why they are linked with chronic kidney disease and advanced renal damage, and what tests and symptoms guide follow-up.

Waxy casts in urine are an abnormal sediment finding most often associated with markedly reduced kidney function and prolonged slow flow through damaged nephrons....

White Blood Cell Casts in Urine: Pyelonephritis, Interstitial Nephritis, and Kidney Infection

Learn what white blood cell casts in urine mean, why they occur in pyelonephritis and interstitial nephritis, and which tests help identify the cause.

White blood cell casts in urine are an important clue that inflammation is occurring inside the kidney, not just in the bladder or urethra....

White Blood Cells in Urine Test: Pyuria, Infection, Inflammation, and Meaning

Learn what white blood cells in urine mean, common pyuria thresholds, how UTI differs from sterile pyuria, and when culture, repeat testing, or urgent care is needed.

White blood cells in urine mean that the urinary tract is inflamed, but they do not automatically prove a bacterial urinary tract infection. The...

Yeast in Urine Microscopy: Candida, Infection, Contamination, and Meaning

Learn what yeast in urine microscopy means, how Candida contamination differs from candiduria and infection, which risk factors matter, and when treatment is needed.

Yeast seen on urine microscopy most often represents Candida, but the finding does not automatically mean a Candida urinary tract infection. Yeast can enter...

Fluid Balance Urine Test Panel: Osmolality, Sodium, Creatinine, and Hydration Status

Understand how urine osmolality, sodium, and creatinine work together to assess hydration, kidney concentration, hyponatremia, polyuria, and fluid balance.

A fluid balance urine test panel combines urine osmolality, sodium, and creatinine to show how the kidneys are concentrating urine and handling water and...

Fractional Excretion of Potassium (FEK) Test: Potassium Balance and Kidney Loss

$Learn how fractional excretion of potassium (FEK) is calculated and interpreted for kidney potassium loss, hypokalemia, hyperkalemia, and aldosterone-related disorders.$

The fractional excretion of potassium (FEK) estimates what percentage of the potassium filtered by the kidneys is ultimately excreted in urine. It is calculated...

Fractional Excretion of Sodium (FENa) Test: Acute Kidney Injury and Volume Status

Learn how FENa is calculated, what values below 1% or above 2% can mean, when diuretics and CKD make it unreliable, and how it fits into acute kidney injury evaluation.

Fractional excretion of sodium (FENa) estimates the percentage of filtered sodium that the kidneys excrete in urine. It is calculated from paired urine and...

Fractional Excretion of Urea (FEUrea) Test: Kidney Injury, Diuretics, and Prerenal AKI

Understand how FEUrea is calculated, what the 35% cutoff means, why diuretics complicate AKI testing, and how FEUrea compares with FENa for prerenal and intrinsic kidney injury.

Fractional excretion of urea (FEUrea, also written FEU or FEUN) estimates the percentage of filtered urea that is excreted in urine. Clinicians mainly use...