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February 24, 2022 | Blood Tests

What is a CBC Test?

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There’s a good chance that you’ve been ordered to do a complete blood count (CBC) test at least one. While this is a top test, you may not know the full details about what this test means, or why it’s important to stay on top of it. We’re breaking down the top things you need to know about CBC tests and share a way to make completing this common lab test easier in the future.  

Understanding the CBC Test 

The CBC test is measures levels of specific types of blood cells and overall blood composition and is used by healthcare providers to gauge changes in a patient’s health and inform the need for any further medical testing or procedures.

Doctors also order CBC tests to measure changes in blood composition over time. Completing your CBC test annually can be useful down the road as your healthcare provider will have a thorough history.  

A standard complete blood count measures total cell counts for: 

  • Red blood cells (transport oxygen) 
  • White blood cells (fight infection) 
  • Hemoglobin (a protein that carries oxygen within red blood cells) 
  • Hematocrit (the ratio of red blood cells to plasma, which is a fluid component of blood) 
  • Platelets (support blood clotting) 

When compared to established normal ranges and your previous counts, your results may signal changes in health, including a possible medical condition. A CBC is a useful way to see how components of your blood are functioning and interacting with other parts of your body.  

What Can a CBC Test Detect? 

A CBC test is not used to diagnose a specific disease or condition. In other words, the results of a CBC test won’t be definitive proof of any specific underlying issue. Instead, the numbers provide general insight that can inform the need for further, more specific testing to find the cause of any symptoms you may be experiencing. The test can also help rule out certain illnesses and help narrow down the cause of symptoms.  

Changes in blood count levels can be indicative of changes to a patient’s overall health, but even counts outside of the normal range may not be considered worrisome by medical experts depending on other factors. It’s important to take the CBC test whenever it is ordered to help establish a more robust medical history and establish blood level baselines.   

Why Don’t Patients Complete Their CBC Tests? 

While important, getting a cbc blood test doesn’t always rank high on busy to-do lists. According to one study, as much as 40% of patients in the US don’t get the medical testing recommended to them by their healthcare providers. The inconvenience of driving to a sample collection location keeps nearly half of patients from following through on lab orders, which could endanger their own health by delaying a potential diagnosis and missing an opportunity for early detection.    

Why Do I Need a CBC Blood Test? 

If you’ve been asked to complete a CBC test, it’s often to learn more about your current state of health. CBC tests are used as part of routine medical examinations and to monitor for health concerns like anemia or certain types of cancer. Again, just because you’re taking a CBC test doesn’t mean you need to worry about these specific issues. Your healthcare provider will let you know what they are looking for ahead of time.  

Patients experiencing symptoms such as light-headedness, fatigue or weakness may undergo a CBC test to determine the cause of these issues. A complete blood count may also be used to monitor an ongoing condition like a blood disorder or to evaluate the impact of medical treatments such as a new prescription or chemotherapy.  

Do I Need to Fast for a CBC Test? 

If the blood sample is only being used for a CBC blood test, patients can eat and drink as they normally would. However, if the sample is being used for other tests, you might have to refrain from eating or drinking certain beverages a certain number of hours before the draw.  

Always check with your healthcare provider to determine if you need to fast before having bloodwork done. If you need to fast, follow the instructions provided by your healthcare professional. Fasting can be an important part of getting accurate information. 

The New Way to Stay on Top of CBC Blood Tests 

Imagine if there was a way to stay on top of orders from your healthcare provider but have it fit your schedule. You’re in luck. With Scarlet Health®, you can complete a CBC blood draw in the comfort of your home or workplace. No more worrying about finding the time, when Scarlet® can meet you where you are. 

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