Idiopathic
Advanced age, thin woman
Psychiatric: Anxiety, Depression
Hypothyroidism
Anemia
Raynaud’s phenomenon; Scleroderma
Weight loss, malnutrition
Chronic severe illness; General poor health
Hypoglycemia
Anorexia Nervosa
Hypopituitarism
Lupus
Hypothalamus dysfuction (it controls body temperature)
Shock
Sepsis
