Presence of protein in the urine is defined as proteinuria. Normally less than 150 mg of protein appears in urine per day.
Massive proteinuria (>3.5 gm/day) is defined as nephrotic syndrome
Symptoms:
Edema (swelling) in the face, legs, or both; frothing of urine.
Causes:
Primary kidney diseases like IgA nephropathy, MPGN, Minimal change disease, Membranous glomerulopathy.
Conditions like Diabetes, Hypertension, Renal vasculitis, SLE, Amyloidosis, Post infectious glomerulonephritis can be associated with nephrotic range proteinuria.
Investigations:
(a) Urine testing —
Dipstick testA spot urine sample collected at any time (a common and convenient method).
Urine that has been collected over 24 hours (a more exact but somewhat inconvenient method)
Microscopic examination to see whether there are cells, crystals, bacteria, or structures called casts.
(b) Blood tests —
Kidney function tests including BUN and creatinine.
Specialised immunological tests.
(c) Kidney biopsy
Management:
Depends on underlying renal or non renal condition.
Diet: Salt restriction. Protein restriction is controversial. Some studies indicate that it may slow progression of disease but concern exists that it may lead to protein malnutrition. Recommended protein intake is 0.8-1 gm/kg/day.
Control of diabetes/ hypertension.
In case of immune mediated injury, steroids and other immuno suppressive medications may be required.
Prognosis: Depends on cause, degree of proteinuria, and presence/ absence of renal dysfunction.
Disclaimer: Please consult your nephrologist for detailed opinion.