The best and the most accurate method to diagnose lead poisoning is directly measuring the venous blood lead levels.

• [{Blood Lead Levels] is the gold standard test for the diagnosis of lead poisoning. ^[1]
• The following result of [[blood lead levels] is confirmatory of lead poisoning:
  • BLL >5mcg/dL ^[2]

Blood Lead Levels= The best test based on the feature

The following result of direct venous blood lead levels in patients is confirmatory of lead poisoning:

• BLL >5mcg/dL
• BLL >40mcg/dL requires treatment with chelating agents

The BLL test should be performed when:

• The patient presented with symptoms like abdominal pain (“lead colic”), joint/muscle aches, short-term memory problems, difficulty concentrating, irritability, anemia and nephropathy is the first step of diagnosis.
• A positive venous blood lead levels >5mcg is detected in the patient, to confirm the diagnosis.

The rest of the main laboratory tests that measure lead effects are:

• free erythrocyte protoporphyrin test ^[3]
• zinc protoporphyrin test
• CBC with blood smear morphology
• blood urea nitrogen
• serum creatinine
• urinalysis

• There are no established criteria for the diagnosis of lead poisoning. What matters in diagnosing lead poisoning is directly measuring the blood lead levels in venous blood.