Headache: It's Giving Me One

Lecture Notes

In this lecture, we are going to talk about the patient who presents with a chief complaint of headache.

As with all chief complaints, the first thing we will do is construct a differential of critical diagnoses. For headache this includes:

  1. Subarachnoid hemorrhage
  2. Meningitis
  3. Intracranial mass
  4. Temporal arteritis
  5. Acute angle glaucoma

So let’s go through the presentation and evaluation for each critical diagnosis.

Subarachnoid hemorrhage (SAH): This will present with a sudden onset headache that is the worst headache of the patient’s life. It is important to determine the amount of time that it took for the headache to reach maximal intensity. You must ask the patient if it took seconds, minutes, hours, or days for the headache to go from: headache onset ---(?)--> max headache pain. If the history sounds consistent with a SAH (seconds to a few minutes for headache to reach maximal intensity) then the patient should undergo a non-contrast CT Head (CTH). If the CTH is negative, a lumbar puncture (LP) should be performed to adequately rule out SAH (this is currently the gold standard for ruling out SAH). It is important to remember that resolution of the headache with pain medications should not deter you from performing the full SAH work up, especially if the initial history is consistent with SAH. The reason you perform an LP after a negative CTH is because the CTH is only sensitive within the first 6 hours of headache onset to identify blood in the brain. After that, the sensitivity of CT plummets and you can only identify bleeding in the brain by CSF analysis. Most patients with a clinically significant or active SAH will have some derangement in neurologic exam or sensorium, therefore it is unlikely you will miss this because the patient usually has altered mental status. The harder patient to diagnose is the one that came in with a headache from a sentinel bleed. A sentinel bleed is a secondary headache that is characterized by sudden, intense, and persistent pain preceding a spontaneous SAH by days or weeks. It is a warning signal from a leaking aneurysm (aka the ticking time bomb). This is what you are trying to diagnose in the emergency room, an unruptured aneurysm before it develops into a clinically significant SAH or death. This is why you must be vigilant and take sudden onset headaches seriously in patients that otherwise have a normal sensorium or neurologic exam AND why the improvement of pain with medications is not a sensitive enough finding to definitively rule out a sentinel bleed.

Intracranial mass: Patients will present with a headache that is worse in the morning better throughout the day. The best imaging for an intracranial mass is an MRI. If you are unable to get an MRI a CTH can be performed to look for edema and other subtle signs for an intracranial mass.

Meningitis: Patients will present with fever, headache, meningismus, and/or altered mental status. An LP can be performed without a CTH if the patient meets the following criteria:

  1. Age< 60
  2. Not immunocompromised
  3. No history of CNS disease
  4. No seizure within 1 week of presentation

If the patient has one of the above features a CTH should be performed prior to LP. If you have a high suspicion for meningitis, be sure to start antibiotics as soon as possible. Do not delay antibiotics until after the CT LP is performed.

Temporal arteritis: Patients will present with fever, headache, and pain over the temporal artery. Do not forget to palpate the temporal artery pulse to assess for tenderness and not just blindly mash the temporal aspect of the head. Additionally, the patient may complain of jaw claudication and visual loss in one eye. If there is a concern for temporal arteritis, an ESR can be sent.

Acute angle glaucoma: Patients will present with a headache and visual changes. An Intraocular pressure can be measured to rule out acute angle glaucoma.


It is important to note that migraines should be diagnosed by a neurologist. If your patient gives a past medical history of migraines, you want to drill down and find out who made the diagnosis (be weary of elderly patients who report new diagnosis of migraines). Also, the patient needs to say that the current headache feels exactly the same as prior migraines for you to anchor on migraine as the cause of the headache.

Now that we have an understanding of our critical differential diagnosis we can construct a presentation for our attending that is focused. If applicable, here is a template that you can use for the beginning of your presentation:

__ YO M/F with a PMH +/- migraines who presents with sudden/gradual onset headache that is/is not the worst headache of his/her life. +/- fever, neck stiffness. +/- worse in the morning better throughout the day. +/- visual changes….


If you have adequately ruled out all of the dangerous causes of headache you can give the following cocktail to treat your patient’s pain.

  1. Benadryl
  2. Reglan/Compazine IV/IM
  3. Acetaminophen 
  4. 1 L NS

ddxof.com Algorithm for Headache

Full ddxof.com article and algorithm on Headache can be found at  https://ddxof.com/headache/

Full ddxof.com article and algorithm on Headache can be found at https://ddxof.com/headache/

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