Font Size

Hemoglobin Levels (cont.)

What Is Hemoglobin S for Sickle Cell Disease?

Sickle cell disease is a genetic alteration that causes some hemoglobin molecules to be defective (the defective hemoglobin is termed hemoglobin S). When red blood cells have hemoglobin S, and are subjected to low oxygen levels, they can become crescent or "sickle shaped" and do not easily move through capillary vessels with small diameters, thus depriving tissues from exchanging oxygen and carbon dioxide. In extreme situations, tissue can begin to die. Sickle cells may lead to anemic conditions because sickle cells have a life-span of about 10–20 days, while normal red blood cells live about 120 days; thus the bone marrow may fall behind in synthesizing new red blood cells. Moreover, dead or dying sickle cells may clog up the spleen as the spleen tries to remove the sickle cell debris from the blood. The common symptoms of sickle cell disease include the following in addition to the symptoms of anemia:

In some individuals, the spleen becomes so damaged that it needs surgical removal. Surgical removal of the spleen makes an individual more susceptible to certain diseases, most notably, pneumococcal pneumonia. Sickle cell disease is fully expressed in individuals that inherit a defective hemoglobin gene from each parent. The individual that inherits only one defective gene has much milder symptoms or no symptoms, and is considered to have sickle cell trait, not sickle cell disease.

Picture of Sickle Cell Red Blood Cell

Medically Reviewed by a Doctor on 9/29/2016

Must Read Articles Related to Hemoglobin Levels

Anemia Anemia can be caused by many conditions and diseases such as iron deficiency, poor diet and nutrition, cancers, bone marrow problems, and more. Symptoms of anem...learn more >>
Chemotherapy Chemotherapy or "chemo" is a treatment for cancer. Depending on the type of cancer an individual has, it can cure cancer, control cancer. or ease cancer symptom...learn more >>
Chronic Obstructive Pulmonary Disease (COPD)
Chronic Obstructive Pulmonary Disease (COPD) Chronic obstructive pulmonary disease (COPD) is a lung condition in which there is a long-lasting obstruction of the airways, and occurs with learn more >>

Patient Comments & Reviews

The eMedicineHealth doctors ask about Hemoglobin:

Hemoglobin - Anemia

Have you been diagnosed with anemia? How did it affect you?

Hemoglobin - High Levels

What was the cause of your high hemoglobin reading?

Hemoglobin - Thalassemia

Do you have thalassemia? Please describe your experience

Hemoglobin - Results

What were the results of your hemoglobin test and what condition did it ultimately help diagnose?

Medical Dictionary