How can I interpret my medical test results or symptoms?

General Approach to Interpreting Medical Test Results

Always interpret abnormal test results in the context of previous results, past medical history, and current clinical condition—never in isolation. 1

Core Principles for Test Interpretation

Context is Critical

• Review historical data first: Compare current results against previous values to identify trends or acute changes 1
• Consider the clinical presentation: The same abnormal value may have different significance depending on symptoms, age, comorbidities, and medications 1
• Magnitude doesn't equal significance: The degree of abnormality doesn't necessarily indicate clinical importance—what matters is which specific analyte is abnormal and the patient's clinical context 1

Confirming Abnormal Results

When you receive an abnormal result, confirmation testing is essential before making major clinical decisions. 1

• For diabetes diagnosis: Requires two abnormal test results—either from the same sample using different tests, or from two separate samples 1
• If discordant results occur (e.g., A1C elevated but fasting glucose normal): Repeat the test that exceeded the diagnostic threshold, considering potential assay interference 1
• For antiphospholipid antibodies: Two consecutive positive tests at least 12 weeks apart are required to rule out transient positivity 1

Common Pitfalls to Avoid

Pre-analytical errors are a major source of false results:

• Glucose samples: Must be centrifuged and separated immediately after collection—samples left at room temperature will show falsely low values 1
• Hemoglobin A1C interference: Can occur with hemoglobin variants (sickle cell trait), postpartum status, HIV on certain medications, or iron deficiency anemia 1
• Anticoagulant effects: Lupus anticoagulant testing during warfarin or direct oral anticoagulants requires special interpretation or pre-test drug removal 1

Structured Approach by Test Category

Laboratory Tests

Initial liver function abnormalities should include: bilirubin, albumin, ALT, ALP, GGT, and complete blood count 1

• Abnormal liver tests warrant investigation with a liver etiology screen regardless of the degree or duration of abnormality 1
• For adults: Include abdominal ultrasound, hepatitis B surface antigen, hepatitis C antibody with PCR if positive, autoantibodies (anti-mitochondrial, anti-smooth muscle, antinuclear), immunoglobulins, ferritin, and transferrin saturation 1

For diabetes monitoring: Discrepancies between capillary blood glucose and A1C suggest hemoglobinopathy, hemolysis, or need for technique/equipment evaluation 1

Cognitive Testing

Brief office-based cognitive tests may miss very mild but clinically important impairment. 1

• Neuropsychological evaluation should include normed testing of: learning and memory (delayed free/cued recall), attention, executive function, visuospatial function, and language 1
• Consider formal neuropsychological testing when: office examination is abnormal but interpretation is uncertain, complex clinical profile exists, or confounding demographic characteristics (limited education, language barriers) are present 1

Imaging Studies

Structural imaging abnormalities require clinical correlation—statistically abnormal doesn't always mean disease. 1

• Computer-based optic nerve imaging (OCT, confocal scanning) must be interpreted alongside clinical examination and other tests to avoid false-positive disease conclusions 1
• Individual findings may fall outside normative databases without representing true pathology 1
• For Alzheimer's disease evaluation: Blood-based biomarkers showing amyloid positivity in patients ≥65 years with typical amnestic syndrome and high concern for AD warrant referral for confirmatory testing 1

When Diagnostic Uncertainty Persists

Use a deliberate, personalized approach—not a "shotgun" testing strategy. 1

• Order additional tests guided by the patient's specific clinical characteristics, risk profile, and biopsychosocial factors 1
• Highly selective advanced testing (Tier 3-4) should involve specialist guidance for atypical, rare, or rapidly progressive conditions 1
• For dementia evaluation with continued uncertainty after structural imaging: FDG-PET can improve diagnostic accuracy by showing patterns of cellular glucose metabolism 1

Documentation and Communication

Test results should be reported with detailed context:

• Include local cutoff values and reference ranges 1
• Provide warnings about potential interferences (anticoagulants, acute phase proteins) 1
• For complex results like lupus anticoagulant: Give a final conclusion (positive/negative) alongside detailed data 1
• Maintain close interaction between laboratory and clinician for proper interpretation 1