Complete Blood Count (CBC) Tests and Lupus

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A complete blood count (CBC) can give you and your lupus treatment team a birds-eye view of your bloodstream & overall health.

And the experts agree, CBC tests should be a regular part of your physical exam. They can even be used to help diagnose lupus

Complete blood count tests give you a lot of information about your body and your health. But, they are actually very simple. If a CBC is the only test you are going in for when you have your blood drawn, you can eat and drink normally. The procedure is also very basic. A phlebotomist will take your blood and send it to a lab. Afterwards, you can go about the rest of your day, no problem. 

With regards to cost, CBCs don’t require much processing so they are fairly low-cost. Many insurance plans will cover the costs of blood tests. However, you may have a copay.

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What is a complete blood count (CBC) measuring?

During a CBC, a lab technician will look at your blood under a microscope. Using a special machine to help them analyze the blood, they take a count of the different blood parts. Each cell type, or – in the case of hematocrit, each measurement – can help hint at what is going on in the body. This can potentially diagnose lupus, or, just as importantly, gauge overall health. The cell types counted in the test are:

Red blood cells

Red blood cells carry oxygen throughout the body. For most people, these important cells are circular with a small dimple in the center. However, for people carrying the sickle-cell gene, a few red blood cells have a different structure that resembles a sickle or crescent moon shape. These miss-formed red blood cells do not carry oxygen as effectively and can also clog vessels in the bloodstream resulting in pain and organ damage.

These unusual blood cells are the cause of Sickle Cell Anemia, a condition that can co-occur in people with lupus. The people at highest risk for developing sickle-cell (people of African, Asian, Central American, South American, Middle Eastern, Indian, and Mediterranean descent) also have an increased risk of lupus. Lupus itself can also cause low levels of red blood cells. 

Fewer red blood cells means less oxygen is being transported to the body. As cells and organs are starved for oxygen, fatigue and brain fog can happen. Anemia also makes organs more susceptible to damage. 

Exactly what causes this type of anemia isn’t always clear in people with lupus. But, catching it early allows people with lupus to pursue treatment options to prevent damage and relieve symptoms. You can read more about lupus-related anemia here.


Hemoglobin is actually a part of the red blood cell. In fact, hemoglobin is the structure that actually carries the oxygen through the bloodstream. Measuring both hemoglobin levels and counting red blood cells helps doctors better diagnose anemia.

Normal levels fall in the range of 11.5 to 15.0 grams per deciliter of blood.

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White blood cells

White blood cells are a part of the immune system and act as the body’s personal army of soldiers. They attack and destroy invaders such as bacteria, viruses, fungi, and other pathogens. White blood cells are important to keeping us healthy. However, they are also an important indicator of the state of the immune system and the potential risk of lupus flares.

What do your white blood cell count results mean?

  • If white blood cell levels are within normal ranges, then it may indicate either a healthy immune system or a lull in inflammation. In either case, this is good because they are still protecting the body.
    • A normal count of white blood cells falls in the range of 4,500-10,000.
  • If white blood cell levels are low, then it means that the person’s immune system has been compromised. This could be because of medications or medical treatments, or they could have recently gotten over a sickness. Their resources have been drained from the battle. People with low white blood cell counts are very vulnerable to infections and may need more help than usual to fight off disease. Lupus – and many of its medications – can lower white blood cell counts.
    • Usually, low white blood cells are only a problem at 2,000 or below.
  • If white blood cell levels are higher than normal, it may indicate that the person is sick and the body is ready to attack. At this stage, it isn’t easy to tell what the white blood cells are attacking. They respond to signal flags that other immune system cells attach to the pathogen. These flags tell them what cells to attack but special tests are required to determine anything more specific than that. High levels of white blood cells mean that the immune system is activated and that there is inflammation in the body even if there are no current symptoms.


Platelets are small proteins in your blood that allow your body to seal and recover from wounds. They move quickly, linking together to form a barrier between the bloodstream and the wound, stopping the bleeding and allowing the body’s natural repair mechanisms to begin fixing the wound.

Normal platelet counts are typically 150,000 to 300,000. Doctors start to be wary at levels below 100,000. Platelet counts below 30,000 require immediate treatment and monitoring. This is because low platelet counts, also known as thrombocytopenia, can make bleeding, both internal and external, both more frequent and more dangerous. 


In addition to counting the cells in your sample, it is important to measure the the proportion of red blood cells to plasma (the liquid portion of your blood). This measurement, called hematocrit, can help confirm a diagnosis of anemia. It can also be an indicator of lung and heart health, hydration & nutrition, and even hint at internal damage or bleeding. 

Normal hematocrit levels come out to around 35-40% red blood cells-to-plasma.

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CBC tests & lupus

A complete blood count test is only one of several tests that help diagnose lupus. Because lupus is so complicated, CBC and other blood tests cannot provide the full picture alone. 

They can, however, help you see what is going on in your bloodstream and catch health problems red-handed, if you excuse the pun. Whether you have confirmed a lupus diagnosis or not, CBC tests can help you better track your health and well-being.

Comments (6)

6 thoughts on “Complete Blood Count (CBC) Tests and Lupus

  1. I also believe I have lupus;especially lately. I have several s/s along with the butterfly rash. Also lately I have had a rash on my forehead and temple area. I also do not have insurance. All my life all I have heard is that I have inflammation. Take this and it will clear up!?? What do you suggest???

  2. I was diagnosed a couple of weeks ago with lupus. They want to do another test but I don’t have insurance and I’m not able to work and the test is around $220. I was given prednisone for 5 days which really helps but once it’s gone, my pain returns. It’s a pain I wouldn’t want anyone to have.

  3. I have several s/s of lupus, and I’ve had one positive ANA and one negative ANA, and haven’t gotten anti-dsDNA or ENA or any other further testing. I have low hemoglobin and hematocrit, and high RDW and platelets. I have a B12 insufficiency and D deficiency. How likely is it that I have lupus? Should I get an other ANA test along with the anti-dsDNA and ENA tests done now, or wait until my next appointment (which is in 2 months…)?

    1. Your bloodwork is very similar to mine, actually. About two months ago, I came up ANA+ (weak positive, 1:80), but am anemic (low hemoglobin, low hematocrit), borderline vit d deficient (I already take 2,000 IUs a day), and vitamin b12 deficient. None of my tiers came up positive, and my physician did not request the complement testing as she thought the rheumatologist would have. On consultation with the rheumatologist, she blew off all of my testing due to my hashimoto’s. I’m waiting to get a second opinion.

      I’d be interested in what your doctors come up with, or what others oh this forum have to say.

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