A high creatinine ratio—commonly the urine albumin-to-creatinine ratio—means excess protein in urine and suggests impaired kidney filtering. It can indicate early kidney damage from diabetes, high blood pressure, infection, or other kidney conditions. A single high result needs repeat testing and further evaluation (blood creatinine, eGFR, blood pressure). Management depends on cause and may include blood pressure and glucose control and specialist referral.

Normal albumin-to-creatinine ratio (ACR) in a spot urine sample is below 30 mg/g (or below 3 mg/mmol). Values between 30–300 mg/g (3–30 mg/mmol) indicate moderately increased albumin (microalbuminuria); above 300 mg/g (>30 mg/mmol) denotes severely increased albuminuria. Persistent elevation suggests kidney damage and warrants repeat testing and medical assessment. Risk factors like diabetes and high blood pressure increase likelihood.

During pregnancy serum creatinine normally falls due to increased glomerular filtration. Typical reference ranges are about 0.4–0.8 mg/dL (35–70 µmol/L). Values up to ~0.9 mg/dL (≈80 µmol/L) may still be acceptable, but persistent creatinine ≈1.0 mg/dL or higher is abnormal in pregnancy and should prompt evaluation for renal dysfunction or pre-eclampsia.

Normal serum creatinine in children varies by age and muscle mass. Typical values: newborns initially 0.3–1.0 mg/dL (falls after the first days), infants/toddlers about 0.2–0.4 mg/dL, school‑aged children roughly 0.3–0.7 mg/dL, and adolescents approach adult ranges (~0.5–1.0 mg/dL). Values and clinical significance should be interpreted in the context of growth and overall health.

You should worry about creatinine ratios when results are persistently abnormal, rise over time, or accompany symptoms. For urine albumin‑to‑creatinine ratio, values ≥30 mg/g warrant monitoring and values >300 mg/g need urgent evaluation. A rising serum creatinine (for example, a ≥50% increase from baseline) or falling eGFR suggests kidney impairment and requires prompt medical review, especially with swelling, reduced urine output, or high blood pressure.

Treating a high creatinine ratio focuses on addressing the cause and protecting kidney function. Rehydrate if volume‑depleted, stop or adjust nephrotoxic drugs (NSAIDs, some antibiotics, certain diabetes meds), control blood pressure and blood sugar, and treat obstructions or infections. Limit dietary protein and salt, monitor kidney function regularly, and consult a nephrologist; dialysis may be needed for severe or progressive renal failure.