Sickle Cell Anemia: Causes, Symptoms, and Treatment

Introduction

Sickle cell anemia is an inherited condition caused by the presence of abnormal hemoglobin. In basic terms, hemoglobin is a protein found in red blood cells whose primary function is carrying oxygen throughout the body. It is this hemoglobin abnormality that produces "sickled," or distorted, red blood cells whose survival is compromised as a result of their distorted shape and fragility. Although the prevalence of the condition varies considerably by region, the Centers for Disease Control and Prevention identifies sickle cell anemia as the most commonly inherited blood disorder in the United States. This paper provides a complete and concise definition of the disorder and its prevalence, details how the condition affects body systems, and reviews how it is treated.

A Detailed Overview of the Condition

In individuals with sickle cell anemia, normal hemoglobin differs significantly from sickle hemoglobin, also known as hemoglobin S. According to Crowley (2009), abnormal hemoglobin results from the alteration of the amino acids that form the globin chain, caused by an abnormality in the genes that control amino acid arrangement in hemoglobin. Crowley also notes that in some cases the functioning of abnormal hemoglobin is not affected. However, in other cases the abnormal hemoglobin may develop unusual properties that effectively impair its functioning.

While normal red blood cells are typically round in shape and can move with relative ease through blood vessels, abnormal red blood cells have their movement significantly impaired — particularly through smaller blood vessels — due to their crescent shape. As a result of this impairment, they commonly become stuck and block other blood cells. This blockage prevents red blood cells from reaching various organs and tissues, eventually causing damage to those organs and tissues. Such blockages are known to trigger what is commonly referred to as a sickle cell crisis episode. During a sickle cell crisis, the individual experiences severe pain caused by the denial of oxygen to a particular body part (Falvo, 2005). Severe obstruction of red blood cell flow may also cause tissue death, also known as necrosis.

Additionally, the fragility of abnormal red blood cells commonly leads to their rupture. This rupture — also known as hemolysis — produces a sustained decrease in red blood cell count, resulting in anemia. According to Khanna (2009), the average lifespan of abnormal red blood cells is between ten and twenty days, whereas normal red blood cells have an average lifespan of up to one hundred and twenty days.

Signs and Symptoms

The signs and symptoms of sickle cell anemia vary considerably from person to person and may range from mild to severe. For infants, signs of sickle cell anemia may not appear until approximately four months after birth, even though the condition is present at birth. In most cases, sickle cell anemia exhibits signs that are either loosely or strongly connected to anemia, with occasional bouts of pain. Most other evident signs and symptoms arise from the complications of the condition.

Individuals with sickle cell anemia may frequently feel weak and fatigued. The U.S. Department of Health and Human Services lists additional symptoms including jaundice, constant headaches, and occasional dizziness. Other symptoms include cold hands and feet and shortness of breath. These signs and symptoms are also linked, in various ways, to anemia. Furthermore, individuals with the condition may experience occasional but sudden body pain — that is, the sickle cell crisis described above. The frequency and severity of pain episodes varies by individual: some people experience severe pain only occasionally, while for others it may be more frequent.

Sickle cell anemia can also be identified based on the complications it produces. According to the U.S. Department of Health and Human Services, these complications may include stroke, leg ulcers or sores, painful and unwanted erections in males, and eye problems. In rare and very serious cases, multiple organ failure may also occur.