Cystatin C

A protein produced by all nucleated cells at a constant rate, filtered by the kidneys. Cystatin C is a more accurate marker of kidney function than creatinine because it's less affected by muscle mass, age, and diet.

A waste product from normal muscle metabolism, filtered by the kidneys. Blood creatinine levels reflect kidney filtration capacity. Elevated levels may indicate impaired kidney function, dehydration, or excessive muscle breakdown.

A waste product from protein breakdown, processed by the liver and excreted by the kidneys. Elevated urea levels can indicate kidney dysfunction, dehydration, high-protein diet, or gastrointestinal bleeding.

An estimated measure of how well your kidneys filter waste from the blood. It's calculated from creatinine levels, age, sex, and race. eGFR is the primary marker used to stage chronic kidney disease.

The primary electrolyte regulating fluid balance and blood pressure. Sodium is essential for nerve impulses and muscle contractions. Abnormal levels can cause confusion, seizures, and cardiac arrhythmias.

A critical electrolyte for heart rhythm, muscle contractions, and nerve function. Both high and low potassium can cause dangerous cardiac arrhythmias. Levels are influenced by kidney function, medications, and diet.

An electrolyte that works with sodium to maintain fluid balance, blood pressure, and acid-base balance. Chloride abnormalities often accompany sodium abnormalities and can indicate dehydration, kidney disease, or metabolic disorders.