The doctor will ask about your symptoms and medical history, and perform a physical exam. The cause of a headache can be difficult to determine. The doctor will ask about the frequency and pattern of your headaches. To help provide answers, keep a diary of:

• When your headaches start and end
• What you were doing at the time
• What you did to try to relieve pain and how effective the treatment was
• Family members with the same condition
• Triggers that you are aware of
• Where the pain is located and where it spreads to
• Other symptoms associated with the pain

Tests to determine the cause of headaches include:

• Neurological exam—The doctor may perform a neurological exam to assess:
  • Muscle strength
  • Coordination
  • Reflexes
  • Sensation
  • Mental status
  • Cranial nerve function
• Blood tests—Blood tests may be done to exclude other causes of your headache. These include blood sugar, a complete blood count looking for anemia or infection, as well as other studies to potentially look for evidence of inflammation.
• X-rays—X-rays of the neck may help determine if arthritis is contributing to a tension headache. Skull x-rays may be taken to check for structural changes responsible for sinusitis.
• CT scan—This is a type of x-ray that uses a computer to make pictures of structures inside the head. A CT scan is used to check for conditions that may cause headaches or to determine if a structural problem is causing chronic sinusitis.
• MRI scan—This is a test that uses magnetic waves to make pictures of structures inside the head. An MRI scan can be used to check for any conditions (tumor or bleeding in head) that may be responsible for your headaches.
• Nasal endoscopy—The doctor uses a thin, lighted tube to look inside your nose and possibly take samples of drainage to be tested for allergies or infection.
• Lumbar puncture (LP, spinal tap)—During this procedure, spinal fluid is collected to look for bleeding, infections, or cancer. The opening pressure may also be measured.

Often, tests are done to rule out causes of your headaches.