Proteinuria, elevated protein in urine, is one of the earliest and most reliable signals of kidney trouble. Healthy kidneys keep protein in the blood where it belongs. When they are damaged or stressed, protein leaks into urine.
What Causes Proteinuria?
The kidneys contain tiny filtering units called glomeruli. When these filters are inflamed, scarred, or damaged, protein, primarily albumin, begins to slip through.
Common causes: – Diabetes, the most common cause worldwide – High blood pressure, damages small blood vessels in the kidneys – APOL1 gene variants, particularly associated with focal segmental glomerulosclerosis (FSGS) – Lupus nephritis, autoimmune inflammation – Infections or dehydration, transient proteinuria that resolves on its own
How Is It Measured?
The urine albumin-to-creatinine ratio (uACR) is the most common test: – Normal: Less than 30 mg/g – Moderately increased: 30–300 mg/g – Severely increased: Over 300 mg/g
Why It Matters, Even When You Feel Fine
Proteinuria rarely causes symptoms until levels are very high. This is what makes it dangerous, by the time most people notice foamy urine or swelling, kidney damage is often already advanced. Regular urine testing for people with diabetes, high blood pressure, or APOL1 genetic risk is the only reliable way to catch it early.
Treatment and Research
Treatment typically involves controlling blood pressure with ACE inhibitors or ARBs, managing blood sugar in diabetic patients, and in some cases, immunosuppressive therapy.
Several active clinical trials are evaluating medications designed to specifically target the causes of proteinuria, including APOL1-related kidney disease. NuLine is currently enrolling kidney study patients. Contact our team to learn whether a trial may be right for you.