Diagnosis
Most headaches can be diagnosed by the clinical history alone. If the symptoms described by the person sound dangerous, further testing with neuroimaging or lumbar puncture may be necessary. Electroencephalography (EEG) is not useful for headache diagnosis.The first step to diagnosing a headache is to determine if the headache is old or new. A "new headache" can be a headache that has started recently, or a chronic headache that has changed character. For example, if a person has chronic weekly headaches with pressure on both sides of his head, and then develops a sudden severe throbbing headache on one side of his head, they have a new headache. Red flags
It can be challenging to differentiate between low-risk, benign headaches and high-risk, dangerous headaches since symptoms are often similar. Headaches that are possibly dangerous require further lab tests and imaging to diagnose.The American College for Emergency Physicians published criteria for low-risk headaches. They are as follows:
age younger than 30 years
features typical of primary headache
history of similar headache
no abnormal findings on neurologic exam
no concerning change in normal headache pattern
no high-risk comorbid conditions (for example, HIV)
no new concerning history or physical examination findingsA number of characteristics make it more likely that the headache is due to potentially dangerous secondary causes which may be life-threatening or cause long-term damage. These "red flag" symptoms mean that a headache warrants further investigation with neuroimaging and lab tests.In general, people complaining of their "first" or "worst" headache warrant imaging and further workup.
If only 2 POUND characteristics are present, tension-type headaches are 60% more likely (likelihood ratio 0.41). Another study found the following factors independently each increase the chance of migraine over tension-type headache: nausea, photophobia, phonophobia, exacerbation by physical activity, unilateral, throbbing quality, chocolate as a headache trigger, and cheese as a headache trigger.Cluster headaches are relatively rare (1 in 1000 people) and are more common in men than women. They present with sudden onset explosive pain around one eye and are accompanied by autonomic symptoms (tearing, runny nose and red eye).Temporomandibular jaw pain (chronic pain in the jaw joint), and cervicogenic headache (headache caused by pain in muscles of the neck) are also possible diagnoses.For chronic, unexplained headaches, keeping a headache diary can be useful for tracking symptoms and identifying triggers, such as association with menstrual cycle, exercise and food. While mobile electronic diaries for smartphones are becoming increasingly common, a recent review found most are developed with a lack of evidence base and scientific expertise. New headaches
New headaches are more likely to be dangerous secondary headaches. They can, however, simply be the first presentation of a chronic headache syndrome, like migraine or tension-type headaches.One recommended diagnostic approach is as follows. If any urgent red flags are present such as visual loss, new seizures, new weakness, new confusion, further workup with imaging and possibly a lumbar puncture should be done (see red flags section for more details).