Migraine is largely diagnosed based on the history given by the patient. Most cases do not require any investigations for diagnosing the same. However, the physician will examine the patient and look out for signs of mental confusion, muscle weakness, speech problems, balancing problems, etc. to rule out other causes of headache ( stroke, tumor, meningitis, sinusitis to name a few).
The treating physician may also suggest certain investigations to rule out other causes of headache such as:
However, as mentioned earlier, these tests do not confirm the diagnosis of migraine but only rule out other causes of headache.