Proteinuuriat

Proteinuuriat, in English commonly called proteinuria, is the presence of an abnormal amount of protein in the urine. It is a sign rather than a disease, reflecting changes in kidney function or handling of proteins by the urinary tract. Proteinuria can be transient, caused by factors such as strenuous exercise, fever, dehydration, or urinary tract infection, and may disappear after those conditions resolve. Persistent proteinuria suggests an underlying renal or systemic problem and requires evaluation.

Measurement and interpretation: Protein in urine is often screened with a urine dipstick test, which is most sensitive to albumin but can miss other proteins at low levels. Quantitative assessment uses the albumin-to-creatinine ratio (ACR) on a spot urine sample or a 24-hour urine collection. Thresholds commonly used are: microalbuminuria (approximately 30-300 mg of albumin per day, or an ACR of about 30-300 mg/g) and overt proteinuria (above ~300 mg/day). In some contexts total protein is reported (PCR). Persistent abnormal results on multiple samples over several months indicate a need for further workup.

Common causes: Glomerular diseases such as diabetic nephropathy or hypertensive kidney disease, primary or secondary glomerulonephritides, and tubulointerstitial disorders can produce proteinuria. Tubular proteinuria (as in Fanconi syndrome) and overflow proteinuria (for example due to excess circulating light chains in multiple myeloma) are other categories. Transient proteinuria can occur with exercise or fever, or in pregnancy.

Evaluation and management: A clinician typically reviews history, measures blood pressure and kidney function, and repeats urine testing to confirm persistence. Management targets the underlying cause and may include renoprotective strategies such as blood pressure control with ACE inhibitors or ARBs, metabolic control in diabetes, and, where appropriate, lifestyle modifications. In some cases referral to a nephrologist is warranted.

Prognosis: Persistent proteinuria is a risk marker for progression of kidney disease and for cardiovascular complications, making accurate assessment and management important.