Laboratory Testing for Migraine Workup
Routine laboratory testing is not recommended for the workup of uncomplicated migraine in patients with a normal neurological examination. 1
When Labs Are NOT Indicated
- Typical migraine presentations with normal neurological examination do not require any laboratory studies 1
- The diagnosis of migraine is clinical, based on history and physical examination using ICHD-3 criteria 1
- Testing should be avoided if it will not lead to a change in management 2
- Testing is not recommended if the patient is not significantly more likely than the general population to have a significant abnormality 2
When Labs SHOULD Be Considered
Laboratory testing becomes appropriate when red flags suggest a secondary headache disorder rather than primary migraine:
Specific Clinical Scenarios Requiring Lab Work:
- New-onset headache in patients over age 50: Consider ESR/CRP to evaluate for temporal arteritis, though ESR can be normal in 10-36% of temporal arteritis cases 3
- Systemic signs or symptoms: CBC, chemistry panel, and targeted testing based on clinical suspicion 4
- Suspected infection: CBC with differential, inflammatory markers 4
- Pregnancy: Pregnancy testing as indicated, particularly before initiating certain medications 1
- Secondary risk factors present: Such as cancer (CBC, chemistry panel) or HIV infection (HIV testing, CD4 count) 4
- Suspected subarachnoid hemorrhage: If lumbar puncture performed, CSF spectrophotometry for xanthochromia (100% sensitive at 12 hours through 2 weeks post-hemorrhage) 3
What the Evidence Shows
The yield of routine laboratory testing in migraine patients with normal examinations is extremely low and does not change management 1, 5. Multiple studies combining over 3,000 neuroimaging scans in headache patients with normal neurological examinations found clinically significant pathology in less than 1% of cases 3.
Common Pitfalls to Avoid
- Do not order routine "headache panels" - there is no evidence-based battery of labs for uncomplicated migraine 5
- Do not confuse "sinus headache" with migraine - this is a common misdiagnosis, and sinus imaging/labs are not indicated 2
- Do not rely solely on ESR to rule out temporal arteritis in older patients with new headaches, as it can be falsely normal 3
- Avoid testing simply to satisfy patient anxiety when clinical features clearly indicate primary migraine 3
Specialized Testing (Research Settings Only)
While various laboratory tests have been studied for phenotyping migraine subtypes (quantitative sensory testing, nociceptive blink reflex, provocation tests with GTN or CGRP), these remain research tools without established clinical utility 6. One study found elevated amylase in 53% of migraine patients, but this finding has no diagnostic or therapeutic implications 7.