cyanotic hands or peripheral cyanosis or blue hands at asian young woman with congenital heart disease

19 blue bluish breathless breathlessness cardiac central changes chronic color congenital covid cyan cyanosis cyanotic dark discoloration discolored discolouration discoloured disease finger fingers fingertips hand hands healthy heart hypoxemia hypoxia lung nails pale pallor palm palmar patient peripheral problem purple respiratory skin smoker smoking stain stained unhealthy