What is the difference between a primary and secondary headache?
A primary headache is a headache that is due to the headache condition itself and not due to another cause. A secondary headache is a headache that is present because of another condition such as a sinus headache from sinusitis.
The three types of primary headache are:
Types of secondary headaches are:
- Sinus headache. By definition, this type of headache should resolve when the course of antibiotics is completed.
- Medication overuse headache. By definition, this type of headache should resolve when the medication being overused is discontinued, e.g. Vicodin (hydrocodone) or Fioricet (butalbital).
- Headaches from illness such as meningitis.
- Post-traumatic headache from the trauma event such as a snow-boarding accident.
- Spinal headache. This type of headache is common after an epidural is given such as during labor.
- Brain tumor or aneurysm headache.
- Cervicogenic headache. This type of headache is related to the underlying neck condition such as degenerative disc disease of the cervical vertebrae.
How we can be sure if a headache is primary or secondary?
Answer: By taking a detailed and thorough headache history when evaluating a patient. I am convinced that the history is the key to headache diagnosis. Keeping a headache diary or journal can provide valuable information as you and your health care provider work together to diagnose and treat your headaches.
A useful way to differentiate between primary and secondary headaches is to look at the following list of questions which is sometimes referred to as the “SNOOP” list:
- Systemic Signs or Symptoms: Look for the presence of fever, weight loss, history of cancer, abnormal blood tests; this could point to meningitis, cancer, or illness to be the cause of the headache.
- Neurologic Exam: if the neurologic exam is abnormal, then a secondary headache should be ruled out. Examples of an abnormal neurological exam include abnormal speech, abnormal gait, confusion, and dizziness.
- Onset: if onset of headache is sudden then a secondary headache such as an aneurysm or a bleed should be suspected. Onset less than 2 weeks could indicate an illness such as meningitis. If the onset was greater than 6 months ago, then this is reassuring and points to a benign headache condition.
- Onset: if less than age 5 or new onset greater than 50 years old then a secondary headache should be ruled out and if older than 50, may require an MRI of the brain. It is unusual for someone who never had migraines to develop them for the first time after the age of 50.
- Progressive: this would refer to a headache pattern that is progressively worsening over time. Even migraine patients can develop a secondary headache such as a tumor or aneurysm so a progressive pattern of worsening headaches in a known migraine individual may require a work-up such as an MRI or spinal tab or blood work.
Reassuring history that indicates a primary headache includes:
- Stable pattern of headache for over 6 months
- Predictable triggers for headache
- The individual feels fine in between headache attacks
It is always important to have your headaches correctly diagnosed. Also, if you are experiencing a fundamental change in the pattern or severity of your headaches, see your health care provider for a careful assessment.