Alphabet soup

With increasing access to medical records and test results through patient “portals” and other vehicles for online access, many patients feel more empowered to take ownership of their health and health care decision making. However, while this access can be enlightening, it can also be accompanied by confusion and frustration as patients struggle to make sense of radiology reports, obscure recommendations and screening test results.

Doctors have long relied on a system of abbreviations and acronyms to simplify record keeping and communication. While this makes things easier for medical professionals, it can be very confusing for the layperson who is trying to make sense of it all.

Laboratory test results are like an alphabet soup of strange acronyms, random numbers and mysterious abbreviations. To make things more confusing, tests results are reported in various units and sometimes as absolute values and other times as ratios and percentages, making it difficult to grasp the greater meaning of the numbers. However, some clarity can be gained by simply taking note of some of the most commonly performed lab tests and what they mean.

CBC, or a Complete Blood Count, is probably the most common lab test performed. In its most basic form, there are four tests that are run. The first is the White Blood Cell count, or WBC. An abnormal elevation of the WBC can be a sign of infection, although certain medications such as steroids can elevate it as well. An abnormally low value can indicate that the immune system is compromised. This can be due to medications such as the chemotherapy drugs used to fight cancer, or diseases such as AIDS that affect the body’s ability to fight infection. A normal WBC count is between about 4,000 and 11,000 white blood cells per microliter of blood.

The next test in the CBC is the hemoglobin. This is a protein found in red blood cells that is responsible for transporting oxygen to the cells. It is responsible for the red color of blood. Normal values generally lie between 12 and 17 grams per deciliter of blood. Low hemoglobin is a sign of anemia, which results when the body is not making enough red blood cells or because of blood loss.

The hematocrit is also a test for anemia, but instead of an absolute number, it is a ratio of the volume of red blood cells to the total volume of blood. For reporting purposes, the ratio is converted to a percentage. Normal values range from the low-30s to the mid- to high-40s depending on the patient’s age, gender and clinical situation. About 35% of the total blood volume of a healthy woman should be red blood cells.

The final value in the complete blood count is the platelet count. Platelets are small disc-shaped cells that are involved in clotting. Platelet abnormalities are less common than abnormalities of other components of the CBC, but their importance in stopping bleeds make them a vital part of the CBC. Low platelet counts can be caused by medications such as heparin or by immune diseases, infections or loss because of bleeding. A normal platelet count is between 150,000 and 450,000 per microliter of blood.

Another common laboratory test is the Basic Metabolic Panel, or BMP. This panel measures electrolytes and kidney function. In most labs, the BMP is comprised of sodium (Na), potassium (K), bicarbonate (CO2), chloride (Cl), calcium (Ca), glucose, blood urea nitrogen (BUN) and creatinine (Cr).

While most people are familiar with basic blood electrolytes and glucose, the last two components, BUN and creatinine, test kidney function. The BUN measures how much urea nitrogen is in the blood. This is a metabolic waste product made by the liver, as it uses protein to make energy. Urea nitrogen is removed from the blood by the kidneys. So, an elevated BUN level can indicate the kidneys are not functioning normally. Normal values are between 7 and 20 milligrams per deciliter of blood. Creatinine, another test of kidney function, is a breakdown product of muscle metabolism. It is also removed from the blood by the kidneys, making it a reliable measure of kidney function. If creatinine levels rise, the kidneys are not functioning normally. Normal creatinine levels are around 0.6 to 1.2 milligrams per deciliter of blood.

A Comprehensive Metabolic Panel, or CMP, is done when additional details are needed. A CMP includes the components of the basic metabolic panel plus additional tests for total protein (TP) and albumin (ALB), which are measures of general nutritional status, and the group of tests known as the liver function tests (LFTs). LFTs are comprised of the transaminases, aspartate aminotransferase (AST) and alanine aminotransferase (ALT), as well as bilirubin (BILI) and alkaline phosphatase (ALK PHOS). Bilirubin is sometimes broken into direct bilirubin and indirect bilirubin, so it may appear on a lab report as total bilirubin (TBILI) and direct (D BILI) and indirect (IBILI). LFTs are an excellent way for doctors to evaluate the function and health of the liver through a simple blood test and, if abnormalities are seen, can guide decisions about further testing.

Some background into what tests are being run from those little tubes of blood will help make the results more comprehensible. In the end, this will improve communication between doctors and patients and allow for more informed health care decision making.