​Differential diagnosis of Cyanosis

​Differential diagnosis of Cyanosis 
-polyarteritis nodosa 
-thoracic outlet syndrome 
-methemoglobinemia 
-reflex sympathetic dystrophy 
-Raynaud’s syndrome 
-cold exposure 
-high altitude 
-severe anemia 
-shunt 
-hypotension 
-valvular heart disease
-congestive heart failure 
-pulmonary embolism 
-pneumonia