Breaking Down Your Blood Test

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Technology and advances in medicine have led to an increasing amount of reliance, by physicians and providers, on clinical testing to provide guidance into diagnosis and treatment plans in today’s healthcare. Over the years, testing has become a more common practice, along with the history and physical, to aid in diagnosis due to improved accuracy, availability of testing and reduced costs and risks of testing.

Although medicine in general is trying to reduce the amount of unnecessary testing performed, as a whole I do not see basic laboratory testing for blood diminishing in its use. Below I’ll go over the “basic blood panel” that is often run by providers and sent to patients who have limited ability to interpret their results.

The following are the most common tests and a brief explanation of how to read your results:

CBC or Complete Blood Count (often comes with a cell differentiation)

This is a common test that can help us recognize infection and cancer based on the white blood cell count (WBC) if it is too high or too low, anemia based on red blood cell count (RBC) or hemoglobin and the ability of the blood to clot based on the platelet count, which can be elevated or diminished.

In general, the WBC should be between 3 - 12. Hemoglobin for women should be >12, and for men, >14. Platelet count should be >150 on testing.

CMP or Complete Metabolic Profile

The main components of this test show electrolyte balance in form of sodium (NA), chloride (CL) and potassium (K), which have many implications. A fasting sample can help us determine glucose (sugar) problems if the number is >100.

In addition, Creatinine and BUN are important factors in determining hydration status and how the kidneys are doing. This leads to a glomerular filtration rate (GFR) that gives us an idea if the kidney is suffering from chronic kidney failure. The panel also looks at the liver functions with bilirubin, AST/ALT, and alkaline phosphate which can detect early signs of fatty liver change or damage from medications.

UA or Urinalysis

This common test assesses hydration of patient through the specific gravity, possible abnormalities based on color and pH. However, the main purpose is to check for luekocytes/nitrites for infections, glucose for possible diabetes and protein/blood for possible early cancers or signs of kidney disease.

Thyroid Studies (TSH, Free T3,T4 and others)

These tests seek to detect thyroid abnormalities. Elevated T3 and T4 will cause the TSH to be very low and could be a sign of HYPERthyroidism, while a low T3/T4 usually leads to elevated TSH and could be a sign of HYPOthyroidism.

Cholesterol or Lipid Panel

This is a very common test that is often hard to understand. The test is broken down into Total Cholesterol (TC), High Density Lipid (HDL), Low Density Lipid (LDL), triglycerides and a total cholesterol to high density lipid ratio (TC/HDL ratio). All are important. The greatest factor in risk is absolute number for LDL. Numbers that are >130 are concerning, while numbers <100 are excellent. HDL is also very important as it protects us from harm from other cholesterol types. Ideally, numbers that are >60 are best, whereas <40 is considered abnormal.

Triglycerides are important as they play a role in inflammation and are more closely linked to how we eat. Numbers that are <150 are excellent while >500 become truly worrisome. The ratio is very important in assessing risk. A number >5 means that the patient is at increased risk.

Hemoglobin A1C or A1C

More commonly ordered, this approximately shows the glucose (sugar) pattern over the past three months. It is a number given as a percentage and can help physicians determine if diabetes is present, if patient is at risk or normal. Percentages >6.5% indicates diabetes, while percentages >5.7 % and <6.5% indicates prediabetes.

Remember that clinical tests are rarely diagnostic of conditions alone. Your provider and healthcare team will always use the history and physical along with clinical course to determine the significance of any lab results that are received. There are ALWAYS exceptions and good communication and follow up with your healthcare team will always lead to improved health.

I hope that this article helps patients to better engage themselves and their healthcare teams in achieving the best outcomes!

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