How to Read Your Blood Test Results

What is a Lab Test?

Lab tests are medical procedures frequently used by healthcare providers to determine diagnosis, create treatment plans, confirm that treatment plans are working, monitor diseases over time, and check your overall health.

Lab tests help doctors check for certain diseases by understanding the functions of your body organs. The most common lab tests evaluate how well your liver, kidneys, thyroid, and heart are working. Lab tests can help diagnose diseases such as cancer, HIV/AIDS, diabetes, anemia, and heart disease. 

What are the Different Types of Lab Tests? 

Each lab test has a specific purpose to help diagnose, screen or monitor a specific disease or condition. There are many different types of lab tests that are commonly collected during a doctor's visit. The most common lab tests collected include:

• Urine sample

• Complete blood count

• Chemistry panel

• Lipid panel

• Thyroid levels

How long does it take to get blood test results? Once labs are collected by healthcare personnel, the labs are either processed in the office or sent to a central laboratory to be processed. Whether tests are processed in-office or at a laboratory nearby, lab tests results are typically available 24 to 48 hours after collection.

Some healthcare facilities have the technology to process lab results in minutes using a special type of medical device called a Point of Care Testing device (POCT). These devices can process results in under 5 minutes, while in-laboratory devices take about 30 to 55 minutes to process. Most doctor's offices will send lab work to laboratory facilities off-site, as POCT is often reserved for inpatient hospital settings.

How to Read Lab Results

Usually, lab test results are displayed through a healthcare online portal in which you can access at any time. Laboratory tests follow strict guidelines on privacy and information sharing. These results can then be sent to your doctor or kept for personal use. 

How do you read a blood report? When reading a blood report, you first need to understand what is being evaluated. The following lab tests are used to measure specific body functions:

• Complete Blood Count (CBC) - Labs used to evaluate your overall health and detect a wide range of disorders including infection, leukemia, and anemia.

• Chemistry Panel (CMP or BMP) - Labs used to evaluate electrolyte balance and status of major body organs.

• Lipid panel - Labs used to evaluate cholesterol and risk for heart attacks and strokes.

• Liver panel - Labs used to evaluate liver function and risk for liver disease.

• Thyroid-stimulating Hormone - Labs used to detect TSH hormones and other thyroid diseases.

• Hemoglobin A1C - Labs used to detect diabetes or pre-diabetes and monitor treatment over time.

Next, you will need to understand what negative, positive, and inconclusive means in regard to lab tests:

• Negative or normal is when the disease or substance was NOT found in the sample.

• Positive or abnormal is when the disease or substance was CONFIRMED in the sample.

• Inconclusive or uncertain is when there was not enough information or sample to make a definitive conclusion.

• WNL is a term used in medicine that means "within normal limits," this is another way of saying that a lab is normal.

For example, your urine sample may result as positive for protein or WBCs, which is abnormal. Oftentimes the letter "H" will be listed next to your lab value, which means high value or higher than the average range. Furthermore, the letter "L" will also be listed next to the value to signify a low value, meaning lower than the average range.

What is the normal range for blood test results? Normal ranges for blood tests are reference points usually defined as 95% of the population falls within that range and set value. This range is determined by collecting data from vast numbers of laboratory tests. Your blood test report will list normal ranges for all blood tests measured next to your value.

What Do Abnormal Blood Tests Mean?

Abnormal blood tests may mean that there is a dysfunction in a specific organ system or that a disease or condition has been found. If you find an abnormal value on your blood test report, make sure to discuss it with your doctor first. It may be something that is easily treatable or could be modified with diet and exercise.

Resist the urge to diagnose yourself with a disease before speaking with your doctor. Preventative care focuses on early detection and promotes overall health. Oftentimes, conditions discovered in their early stages have better outcomes.

What Can Affect Blood Test Results?

Test results give healthcare providers part of the clinical picture. Each lab helps paint the clinical picture by giving evidence of certain conditions, or specific diseases. Blood lab test results can be affected by certain things including food and drinks. 

A fasting blood glucose level or fasting lipid panel will not be accurate if you consume food or beverages 8 hours before lab collection. Collecting lab tests when you have eaten may give false data, thus making it important to be honest with your provider when collecting blood samples. If you do not fast, the results may not be accurate. In general, not fasting can be accounted for, so all you need to do is be honest and tell your doctor. 

Other factors that can affect blood test results include:

• Vigorous exercise (may falsely elevate kidney function tests).

• Stress (may increase cortisol levels that would otherwise be normal if the stress was managed).

• Being ill (may show abnormal white blood cell counts during acute illness).

• Medications can skew test results (Antibiotics, antidepressants, and steroids).

• Lab testing variations (human error in lab settings).

It is important to follow instructions when blood work is being collected. Verify with your doctor that you must fast prior to bloodwork or any other specific instructions. Your doctor will also ask for an updated list of medications and vitamins you take before blood tests are collected. 

Talk to a Doctor About Your Blood Test Results

Reviewing blood work results can be overwhelming. At PlushCare, our doctors can help order labs and review labs and blood test results. Book an appointment today to speak with a PlushCare doctor about your blood tests and if you need additional testing.

Read More About Blood Tests

• Get Lab Work

• STD Testing Online

Sources

• Mayo Clinic. Complete blood count (CBC). Accessed on October 11, 2021 at https://www.mayoclinic.org/tests-procedures/complete-blood-count/about/pac-20384919 

• MedlinePlus. How to understand your lab results. Accessed on October 11, 2021 at https://medlineplus.gov/lab-tests/how-to-understand-your-lab-results/

• MedlinePlus. Complete Blood Count (CBC). Accessed on October 11, 2021 at https://medlineplus.gov/lab-tests/complete-blood-count-cbc/