Diagnosis of a stroke is currently based mostly on non-laboratory testing. Researchers continue to try to find laboratory tests, such as stroke biomarkers, that could be used in stroke screening, diagnosis, treatment, and management. Two possibilities of biomarkers that could be helpful in risk assessment are Lp-PLA2 and N-methyl-D-aspartate neuroreceptors (NMDAR), while candidates for stroke diagnosis include antibodies to NR2A/2B and metalloproteinases (MMPs). It may be that a panel of biomarkers would be most effective as a diagnostic or risk assessment tool. These tests are not yet widely available, and their uses are mainly in research studies at present.

Other laboratory tests may be ordered to evaluate a patient suspected of having had a stroke or to rule it out, including:

• Complete blood count (CBC)
• Prothrombin time (PT) and INR
• Partial thromboplastin time (PTT)
• Blood glucose
• Electrolytes
• Cholesterol, HDL, and LDL
• Antinuclear antibodies (ANA)
• Antiphospholipid antibodies (APL)
• Anticardiolipin antibodies (ACL)
• Lupus anticoagulant (LA)
• Blood culture
• Troponin
• Creatine kinase (CK)
• Antithrombin III
• Protein C, Protein S
• Factor V Leiden
• Erythrocyte sedimentation rate (ESR)
• Hemoglobin electrophoresis
• Homocysteine
• Syphilis (VDRL, FTA, others)
• Toxicology screen (serum or urine )