What to expect from a blood test for chronic kidney disease

The laboratory may measure creatinine and use it to estimate how well your kidneys filter blood. It can also check electrolytes, blood glucose, and blood counts, depending on your symptoms and medical history. One result is interpreted alongside earlier results, blood pressure, urine findings, medicines, and conditions such as diabetes. A change may need repeat testing rather than an immediate diagnosis.

Ask whether you need to fast or change the timing of any medicine; many kidney blood tests do not require fasting, but the requested panel determines preparation. Tell the clinician about supplements, recent illness, vomiting, diarrhoea, and medicines that may affect kidney function. Drink normally unless you were given different instructions. A small bruise or tenderness at the needle site can occur.

Contact a clinician promptly if you have much less urine, new swelling, breathlessness, persistent vomiting, confusion, or severe weakness. Seek urgent help for severe breathlessness, chest pain, collapse, or sudden confusion. These symptoms need assessment regardless of whether a blood test has already been arranged.

Which kidney markers are being tested? Has my result changed from a previous test? Do I need a urine test or repeat blood test? Could any medicine, supplement, dehydration, or recent illness affect the result?