Physiological Variables That Can Affect Blood


Are you considering a career in the field of Phlebotomy? As you begin your training and become familiar with the numerous processes and procedures of the job, you should also have an understanding of the various physiological variables that can affect a patient’s blood when collecting samples for testing.

One of the more obvious variables to consider is the age of the patient. Compared with adults, newborns typically have higher values of red and white blood cells. Elderly patients may have higher levels of creatinine present in their blood samples, as kidney function tends to decline with age.

Diet can also affect the composition of blood. A diet that includes foods with high sugar will produce high glucose levels in the blood that can last for several hours. A diet that includes a lot of fatty foods will increase the fat content in blood, making plasma appear cloudy. If the patient is not drinking enough fluids and is dehydrated, this can also affect the blood, causing it to become more concentrated.

Even geography can play a role, as altitude can greatly affect the number of red blood cells in a patient’s blood. To meet oxygen needs, the body will produce more red blood cells due to the decreased oxygen levels found at higher altitudes.

Drug therapy treatments like chemotherapy can decrease white blood cells and platelets, and alter the concentrations of blood analytes. Or, if the patient is taking a drug with steroids or diuretics, this can increase calcium and glucose levels and decrease the levels of sodium and potassium.

Because Phlebotomists are responsible for collecting blood samples before they are taken to the laboratory for testing, it is important for them to be aware of the various physiological factors that have the potential to affect and influence test results. If you’re interested in playing a critical role in the diagnosis and treatment of disease, contact Arizona College to learn about our Phlebotomy training program.

Information in this blog post is accurate as of September 12, 2013.