What does the term cyanotic describe?

The term cyanotic specifically refers to a bluish discoloration of the skin and mucous membranes that occurs due to low oxygen levels in the blood. When the body is not receiving enough oxygen, hemoglobin in the blood can become deoxygenated, leading to this distinctive blue coloring, particularly observable in areas with thinner skin, such as the lips and fingertips.

In contrast to the other options, which describe different conditions or symptoms, the focus of cyanosis is on the oxygenation status of blood. Redness in mucous membranes typically suggests increased blood flow or inflammation rather than a deficiency in oxygen. Discoloration of the eyes can be caused by a variety of issues, including conjunctival inflammation or infection, and does not specifically refer to cyanosis. Lastly, a type of skin infection would involve signs of inflammation or infection, which do not relate to the lack of oxygen that defines cyanotic conditions. Therefore, the correct identification of cyanotic as related to bluish skin color due to lack of oxygen aligns directly with its medical definition and presentation.