What should you know about an LFT and RFT blood test?

LFT results may include enzymes, bilirubin and proteins, which can point towards liver irritation, bile-flow problems or reduced protein production. RFT results commonly include creatinine, urea and electrolytes, with an estimated filtration measure used to understand kidney performance. Abnormal values can have several explanations, including dehydration, medicines, infection or an underlying condition such as Chronic Kidney Disease or Anaemia.

Follow the laboratory instructions about fasting, fluids and regular medicines; do not stop a prescribed medicine unless the clinician tells you to. Tell the team about supplements, recent illness and strenuous exercise. Afterward, ask which values were outside the laboratory range and whether repeat testing or a urine test is needed. A single altered result may be checked against earlier results.

Contact a clinician promptly if you have yellowing of the skin or eyes, very dark urine, severe abdominal pain, marked swelling, confusion, much less urine, chest pain or trouble breathing. Seek urgent help for sudden severe symptoms or if you are too unwell to drink. The urgency depends on symptoms and the actual results, not on the test name alone.

Ask which liver or kidney marker changed, how it compares with your previous result, and whether a medicine, fluid loss or recent infection could explain it. Clarify whether you need repeat blood testing, urine testing, imaging or referral, and what symptoms should prompt earlier contact.