Table 1.

Classification of chronic primary pain [4, 5].

Diagnostic entity	Subcategory
Chronic widespread pain	(i) Fibromyalgia
CRPS	(i) CRPS-1 (ii) CRPS-2
Chronic primary headache or orofacial pain	(i) Chronic migraine (ii) Chronic tension-type headache (iii) Trigeminal autonomic cephalalgias (iv) Chronic primary temporomandibular disorder pains (v) Burning mouth syndrome (vi) Chronic primary orofacial pain
Chronic primary visceral pain	(i) Chronic primary chest pain syndrome (ii) Chronic primary epigastric pain syndrome (iii) Irritable bowel syndrome (iv) Chronic primary abdominal pain syndrome (v) Chronic primary bladder pain syndrome (vi) Chronic primary pelvic pain syndrome
Chronic primary musculoskeletal pain	(i) Chronic primary low back pain (ii) Chronic primary cervical pain (iii) Chronic primary thoracic pain (iv) Chronic primary limb pain

CRPS: chronic regional pain syndrome. Underlined: conditions included in this review.