Before you come to the lab
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Confirm test requirements: Call the lab or check your appointment note to confirm fasting, medication, or timing instructions.
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Schedule smartly: Book morning slots for fasting tests so the fasting window is overnight.
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Bring ID and prescriptions: Carry photo ID, doctor’s requisition, and a list of current medications.
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Hydrate with water: Water is usually allowed and helps with blood draws.
Common tests and how to prepare
Complete Blood Count (CBC)
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No fasting usually required: Eat normally unless your doctor instructs otherwise.
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Avoid heavy exercise: Strenuous activity before the test can alter some values.
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Inform about medications: Blood thinners or supplements may affect results.
Lipid Profile (Cholesterol)
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Fasting often required 8–12 hours: Avoid food and caloric drinks; water is fine.
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Avoid alcohol 24 hours prior: Alcohol can temporarily change lipid levels.
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Take usual meds unless told otherwise: Confirm with your physician.
Blood Glucose and HbA1c
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Fasting glucose: 8–12 hours fasting: Follow fasting instructions exactly for accurate fasting glucose.
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HbA1c: no fasting needed: Reflects average glucose over months and usually doesn’t require fasting.
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Bring diabetes meds and snacks: If you’re diabetic, discuss medication timing with your clinician.
Urine Tests
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Follow collection instructions: Some tests need midstream clean-catch samples; others require first-morning urine.
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Avoid contamination: Clean hands and follow collection steps to prevent false positives.
PCR and Molecular Tests
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Follow swab or sample prep rules: For respiratory PCR, avoid eating, drinking, or smoking shortly before sampling as instructed.
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Inform about recent vaccinations or infections: This context can affect interpretation.