Table 1.

FM classes

Class	Description	Demographics: sex, %; age, mean (SD)	Main comorbidities	Body region prominence	Main secondary conditions	Main treatment focus
1. With three subclasses	Regional FM with classic symptoms	77.9% females, 55.3 (16.5) years; 22.1% males, 55.4 (16.5) years	Interstitial cystitis, muscle spasm, spinal arthritis	Knee, cervical, shoulder, arm, chest	GERD, osteoporosis, RLS	Facets and spinal cord stimulators
2. With two subclasses	Generalized FM with increasing widespread pain and additional symptoms	81.6% females, 61.4 (17.3) years; 18.4% males, 58.9 (17.2) years	Arthritis, upper	Chest, lumbar/hip, and significant increase in knee	GERD, RLS, polio	Epidurals, facets, spinal cord stimulators, bursa/trigger point injections, cervical/thoracic injections
3. With three subclasses	Advanced FM with associated conditions, increasing widespread pain, increased sleep disturbance, and chemical sensitivity	74.2% females, 59.8 (18.0) years; 25.8% males, 61.4 (21.4) years	Arthritis, upper body/limb pain, cervical conditions, migraine	Chest, lumbar/hip, and significant increase in knee	GERD, RLS, polio	Epidurals, facets, spinal cord stimulators, bursa/trigger point injections, cervical/thoracic injections
4. With no subclasses	Secondary FM reactive to disease	80.5% females; 61.3 (17.8) years; 19.5% males, 49.4 (17.0) years	Chronic pain syndrome, joint/limb pain	Chest	MS, lupus, TMJ, IBS	Joint and bursa injections

Abbreviations: FM, fibromyalgia; GERD, gastroesophageal reflux disease; IBS, irritable bowel syndrome; MS, multiple sclerosis; TMJ, temporomandibular joint disorder; RLS, restless leg syndrome.