​A chart summary article teaches you to distinguish between primary and secondary headaches

Headache is one of the most common clinical symptoms, and about 20% of patients in neurology outpatient clinics complain of "headache"
.

Although almost everyone has experienced headache more than once, it is difficult to define exactly, usually involving intracranial or extracranial lesions that stimulate pain-sensitive structures, causing localization to the upper half of the skull (the brow arch, the superior helix, and the external occipital carina).
The pain above the line) is collectively referred to as headache
.

Classification of Headaches The International Classification of Headaches, 3rd edition (ICHD-3) [1] divides headaches into three main categories: primary headaches, secondary headaches, painful cranial neuropathy and other facial pain, and other headaches
.

Each type of headache can be further divided into 2 to 9 subtypes
.

The classification of primary headaches is shown in Figure 1 below
.

Figure 1 Classification of primary headache can be divided into acute headache (duration within 2 weeks), subacute headache (duration of 2 weeks to 3 months) and chronic headache (duration of more than 3 months, more than half of days with headache attacks lasting more than 2 hours per day)
.

The classification of headaches is described above, so what are these different types of headaches caused by and how are headaches diagnosed? Let's take a look at the causes of different types of headaches and the process of diagnosing headaches
.

 Causes of Headaches Primary Headaches The causes of primary headaches are unknown, in fact, for decades, most research has focused on primary headaches, especially migraines
.

Migraine may be related to genetic factors, endocrine and metabolic factors, diet and mental factors [2]
.

Tension-type headache may be related to a variety of factors, such as contraction or ischemia of pericranial muscle or myofascial structures, disturbance of intracellular and extracellular potassium ion transport, sensitization of central nociceptive pathways, and dysfunction of nociceptive pathways
.

In addition, tension-type headache is also affected by genetic, environmental and psychosocial factors [3]
.

The etiology of cluster headache is unknown, and its periodic, rhythmic attacks and signs of trigeminal autonomic reflex suggest hypothalamic dysfunction, but the etiology of hypothalamic dysfunction and how the trigeminal autonomic nerve is activated is still unclear [4]
.

Secondary headache Secondary headache is a symptom of a disease.
It is estimated that about 18% of headache patients are secondary.
In the elderly population, common secondary causes include giant cell arteritis, subdural Hematoma, intracranial tumor, stroke, central infection, etc.
[5]
.

Common secondary causes of children and adolescents include infection, trauma, tumor, cerebrovascular disease, etc.
[6]
.

In the emergency department, although 95% of headache patients are primary, it is necessary to carefully exclude secondary causes that require urgent intervention, such as meningitis, subarachnoid hemorrhage, angle-closure glaucoma, and cerebral artery dissection [7]
.

Flowchart of diagnosis of headache What about headaches and secondary headaches? How should patients be interviewed? For the diagnosis and differential diagnosis of headache, a detailed medical history is the most important, including the trigger, rapid onset, nature, location, and degree of headache, accompanying symptoms, factors that alleviate and aggravate, past history and family history
.

 When should a detailed examination be necessary to clarify or exclude secondary headaches? The initial evaluation of headache can be carried out according to "SNOOP".
When the patient has the following "warnings", it indicates that a detailed examination is needed to confirm or exclude secondary headache: ① Systemic (systemic disease): infection symptoms and signs, history of malignant tumor, pregnancy/puerperium , immunocompromised state, etc.
; ② Neurologic (neurological symptoms and signs): disturbance of consciousness, mental changes, seizures, speech disorders, papilledema, hemiplegia, ataxia, etc.
; ③ Onset (onset form): elderly men New-onset, sudden severe headache; ④Other (other): trauma, neck massage, postural-related headache, eye pain with autonomic symptoms; ⑤Past (past medical history): past history of headache, medication, hypertension, History of sinusitis,
etc.
Table 1 Relevant examinations for
 excluding secondary headaches

References: [1] Headache classification committee of the international headache society (IHS) the international classification of headachedisorders, 3rd edition[J].
Cephalalgia, 2018, 38(1): 1-211.
[2] Do TP, Remmers A, Schytz HW, et al.
Red and orange flags for secondaryheadaches in clinical practice: SNNOOP10 list[J].
Neurology, 2019, 92(3):134-144.
[3] Steel SJ, Robertson CE, Whealy MA.
Current Understanding of thePathophysiology and Approach to Tension-Type Headache[J].
Curr Neurol NeurosciRep, 2021, 21(10):56.
(Impact factor: 5.
081)[4] Hoffmann J, May A.
Diagnosis, pathophysiology, and management ofcluster headache[J ].
Lancet Neurol, 2018, 17(1):75-83.
(Impact factor: 44.
182) [5] Sharma TL.
Common Primary and Secondary Causes of Headache in the Elderly[J].
Headache.
2018, 58(3): 479-484.
(Impact factor: 5.
887) [6] Dao JM, Qubty W.
Headache Diagnosis in Children and Adolescents[J].
Curr Pain Headache Rep, 2018, 22(3):17.
(Impact factor: 3.
494)[7] Filler L, Akhter M, Nimlos P.
Evaluation and Management of the Emergency Department Headache[J].
Semin Neurol, 2019, 39( 1):20-26.
(Impact factor: 3.
420)[8] Lipton RB, Bigal ME, Steiner TJ, et al.
Classification of primaryheadaches[J].
Neurology, 2004, 63(3): 427-435.
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