Final answer:
Cyanosis is a change in skin color characterized by a bluish or grayish discoloration of the skin and mucous membranes. It occurs when there is a reduced amount of oxygen in the blood.
Step-by-step explanation:
Cyanosis is a change in skin color characterized by a bluish or grayish discoloration of the skin and mucous membranes. It occurs when there is a reduced amount of oxygen in the blood, causing deoxyhemoglobin to dominate and give the skin a blue appearance. This condition can be seen in individuals experiencing difficulty in breathing due to asthma or a heart attack.