Complete Blood Count (CBC): What It Is, How It Is Done, and What Your Results Mean

What is this test? A complete blood count, or CBC, is one of the most common blood tests. It measures the cells in your blood, including red blood cells, white blood cells, hemoglobin, hematocrit, and platelets, giving your healthcare provider a broad picture of your overall health.

The Mouth Bacteria Culture test, also called an aerobic bacterial culture from oral specimen, is a laboratory test that collects a sample from your mouth to identify what types of aerobic bacteria are present. Aerobic bacteria are microorganisms that need oxygen to grow. This test helps doctors find out if certain bacteria are causing infection in your mouth, throat, or surrounding areas.

How is the sample collected? The sample is collected through a simple blood draw. A healthcare professional will wrap a band around your upper arm, clean the skin at the inside of your elbow, and insert a small needle into a vein to fill one or more collection tubes. The procedure takes only a few minutes, and you may feel a brief pinch before a bandage is applied.

A healthcare professional will use a sterile swab to collect cells or fluid from your mouth, gums, tongue, throat, or any infected area. The collection process is quick and may cause mild discomfort. After collection, the sample is sent to a laboratory where it is placed in special containers that allow bacteria to grow and be identified.

Why might I need this test? Your provider may order this test as part of a routine checkup, to look into symptoms such as fatigue, weakness, fever, unusual bruising, or unexplained weight loss, to help diagnose conditions like anemia, infection, or bleeding disorders, or to monitor an existing condition and how well your treatment is working.

Your doctor may order this test if you have symptoms such as persistent sore throat, mouth pain, swelling, bad breath that won't go away, white patches in your mouth, or slow-healing mouth sores. It is also used to diagnose conditions like oral infections, tonsillitis, abscesses, or to determine the cause of unexplained mouth or throat symptoms.

What do the results mean? Your report compares your blood cell levels with normal reference ranges. Low red blood cell counts or hemoglobin may suggest anemia, while a high white blood cell count can point to infection or inflammation, and abnormal platelet levels may affect how your blood clots. Your provider will interpret your results together with your medical history, symptoms, and other tests to decide whether any follow-up is needed.

Results typically show which types of bacteria were found in your sample. If harmful bacteria are identified, the report will also include sensitivity testing, which shows which antibiotics can effectively treat the infection. If no pathogenic bacteria are found, your symptoms may be caused by viruses, fungi, or non-infectious conditions.