Which condition is caused by an increased blood concentration of deoxyhemoglobin?

An increased blood concentration of deoxyhemoglobin leads to cyanosis, which is characterized by a bluish discoloration of the skin and mucous membranes. This condition occurs when there is an insufficient amount of oxygen in the blood, resulting in an elevated level of deoxygenated hemoglobin. When hemoglobin releases oxygen to tissues, it transitions to deoxyhemoglobin, which absorbs light differently than its oxygenated form. Consequently, increased concentrations of deoxyhemoglobin can give the skin a bluish tint, particularly noticeable in areas with thinner skin, such as the lips and fingertips.

In contrast, conditions like anemia, leukemia, and thrombocytopenia do not primarily result from elevated deoxyhemoglobin. Anemia involves a deficiency of red blood cells or hemoglobin, which may cause pallor but not specifically blue discoloration. Leukemia is a type of cancer affecting white blood cells, and thrombocytopenia is a condition characterized by a low platelet count, none of which directly relate to increased levels of deoxyhemoglobin and its associated symptoms. Thus, the distinctive presentation of cyanosis is directly attributable to the increased deoxyhemoglobin concentration.