During an evaluation for migraines, physicians take the patient’s medical history and perform a physical examination. While collecting a patient’s medical history, physicians may ask the patient about their symptoms. They will ask if there is a family history of migraines. Typically, physical examinations performed on patients with migraines yield no findings.

The patient may be asked to complete a pain assessment form, such as the  Migraine Disability Assessment (MIDAS) Questionnaire, which was developed to help physicians identify sufferers most in need of care.

Information provided during the evaluation can help physicians determine whether a patient’s symptoms are the result of an underlying medical condition, such as a brain tumor or aneurysm.   

A number of diagnostic tests may be ordered to rule out other potential causes. These may include:

• MRI (magnetic resonance imaging). MRIs use a powerful magnetic field to create images of structures and organs within the body, allowing a computer to produce clear cross-sectional or three-dimensional images. This test may be ordered to rule out sinus inflammation, brain masses and a number of other causes.

• CAT scan (computed axial tomography). This test allows for multiple x-rays to be taken from different angles around the patient. A computer analyzes the "slices" or cross-sectional images. Frequently after the first set of images is taken, the patient receives an intravenous (I.V.) injection of a contrast agent (dye) to better outline the body parts. Then a second set of images is taken. This test may be ordered to rule out sinus inflammation, brain masses and a number of other causes.
  
  
• Electroencephalogram (EEG). Electrodes are placed on the head to measure the brain’s electrical activity. This test may be performed to exclude seizures.
  
  
• Spinal tap (lumbar puncture). This procedure uses a needle to remove a sample of cerebrospinal fluid (CSF) from between vertebrae in the lower spine. Although this test is rarely performed, it may be ordered to rule out encephalitis, meningitis, subarachnoid hemorrhage or other possible underlying conditions that can cause severe headaches.

No tests are available yet to confirm the diagnosis of a migraine. As a result, migraines are often misdiagnosed as sinus headaches or tension headaches.