What is the major form of hemoglobin in adults?

The major form of hemoglobin in adults is Hemoglobin A. This type of hemoglobin is composed of two alpha and two beta chains, and it constitutes approximately 95-98% of the hemoglobin found in healthy adults. Hemoglobin A is essential for transporting oxygen from the lungs to the tissues and plays a critical role in maintaining normal physiological functions.

Hemoglobin F, primarily found in fetal life, is gradually replaced by Hemoglobin A after birth and typically comprises a very small percentage of adult hemoglobin. Hemoglobin C and Hemoglobin S are variations that can lead to disorders such as thalassemia and sickle cell disease, respectively, and are not predominant in healthy adults. Therefore, the predominant presence of Hemoglobin A in adults reflects its crucial role in oxygen transport and overall health.