Urea

Urea levels rise when kidney function is reduced, protein intake is high, or the body is dehydrated. Low levels may occur with severe liver disease or malnutrition. Monitoring urea helps assess kidney and liver function as well as protein balance in the body.

Most adults benefit from yearly urea testing as part of standard kidney screening. If urea is elevated, retest after correcting hydration and recent dietary protein.

At baseline / for screening: Once every 12 months from age 30 as part of a kidney panel. More frequently, every 3 to 6 months, if you have hypertension, type 2 diabetes, chronic kidney disease, or take medication processed through the kidneys.

When monitoring an intervention or change: Retest 2 to 4 weeks after starting a new medication that affects the kidneys (ACE inhibitor, ARB, SGLT2 inhibitor, diuretic, NSAID, certain antibiotics) to confirm stable function. After a meaningful change in blood pressure or diabetes control, retest at 3 months. Hydration on the morning of the draw can shift creatinine-based numbers, so reproduce conditions for reliable trend tracking.

Note: Urea rises with high protein intake, dehydration, GI bleeding, and corticosteroid use, often independent of kidney function. Wait 48 hours after high-protein meals and ensure normal hydration before reading the next value as a stable baseline.