Methemoglobinemia is a blood disorder where an abnormal amount of methemoglobin is produced. This form of hemoglobin cannot effectively carry oxygen, leading to reduced oxygen delivery to the body's tissues. Symptoms may include a bluish tint to the skin, shortness of breath, and fatigue. The condition can be caused by exposure to certain chemicals, medications, or inherited genetic factors. Treatment often involves the administration of methylene blue, which helps convert methemoglobin back to normal hemoglobin, restoring the blood's ability to transport oxygen effectively.