Complete Blood Count (CBC)
Also known as: CBC, Full Blood Count, FBC, Blood Panel
A complete blood count (CBC) is one of the most commonly ordered blood tests. It measures the types and numbers of cells in your blood, including red blood cells, white blood cells, and platelets. A CBC provides a broad snapshot of your overall health and can help detect a wide range of disorders.
Purpose
Screening for general health during routine checkups. Diagnosing infections, anemia, blood disorders, and immune system conditions. Monitoring ongoing treatments such as chemotherapy that affect blood cells. Evaluating unexplained symptoms like fatigue, weakness, fever, bruising, or bleeding.
Preparation
Generally no special preparation is needed. If additional tests are being drawn at the same time (such as a metabolic panel), your doctor may ask you to fast for 8–12 hours beforehand. Continue taking your regular medications unless your doctor advises otherwise.
Procedure
A healthcare professional cleans the skin on the inside of your elbow or the back of your hand with an antiseptic wipe. An elastic band (tourniquet) is wrapped around your upper arm to make the veins swell with blood. A needle is inserted into a vein, and blood is drawn into one or more collection tubes. The tourniquet is removed and a bandage is applied. The entire process takes about 5 minutes.
Normal Range
Red blood cells (RBC): Men 4.7–6.1 million/mcL, Women 4.2–5.4 million/mcL. Hemoglobin: Men 13.5–17.5 g/dL, Women 12.0–16.0 g/dL. Hematocrit: Men 38.3–48.6%, Women 35.5–44.9%. White blood cells (WBC): 4,500–11,000/mcL. Platelets: 150,000–400,000/mcL. Note: Normal ranges may vary slightly between laboratories.
Abnormal Results
Low RBC/hemoglobin may indicate anemia, nutritional deficiency, bone marrow problems, or chronic disease. High RBC may suggest dehydration, lung disease, or polycythemia vera. Low WBC may indicate bone marrow damage, autoimmune disease, or severe infection. High WBC may suggest infection, inflammation, immune disorder, or leukemia. Low platelets may indicate bleeding disorders or certain medications. High platelets may suggest inflammation, infection, or bone marrow disorder.
Risks
Minimal risks. You may experience slight pain, bruising, or bleeding at the needle site. In rare cases, the site may become infected. Some people may feel lightheaded or faint during or after the blood draw.
Turnaround Time
Results are typically available within 24 hours. Some facilities offer same-day results.
Estimated Cost
$15–$100 without insurance. Usually covered by most insurance plans as a routine screening test.
Frequently Asked Questions
What is a Complete Blood Count (CBC) test?▼
A complete blood count (CBC) is one of the most commonly ordered blood tests. It measures the types and numbers of cells in your blood, including red blood cells, white blood cells, and platelets. A CBC provides a broad snapshot of your overall health and can help detect a wide range of disorders.
What is the normal range for a Complete Blood Count (CBC)?▼
Red blood cells (RBC): Men 4.7–6.1 million/mcL, Women 4.2–5.4 million/mcL. Hemoglobin: Men 13.5–17.5 g/dL, Women 12.0–16.0 g/dL. Hematocrit: Men 38.3–48.6%, Women 35.5–44.9%. White blood cells (WBC): 4,500–11,000/mcL. Platelets: 150,000–400,000/mcL. Note: Normal ranges may vary slightly between laboratories.
How do I prepare for a Complete Blood Count (CBC)?▼
Generally no special preparation is needed. If additional tests are being drawn at the same time (such as a metabolic panel), your doctor may ask you to fast for 8–12 hours beforehand. Continue taking your regular medications unless your doctor advises otherwise.
What do abnormal Complete Blood Count (CBC) results mean?▼
Low RBC/hemoglobin may indicate anemia, nutritional deficiency, bone marrow problems, or chronic disease. High RBC may suggest dehydration, lung disease, or polycythemia vera. Low WBC may indicate bone marrow damage, autoimmune disease, or severe infection. High WBC may suggest infection, inflammation, immune disorder, or leukemia. Low platelets may indicate bleeding disorders or certain medications. High platelets may suggest inflammation, infection, or bone marrow disorder.
Related Lab Tests
Basic Metabolic Panel (BMP)
Chemistry
The basic metabolic panel is a group of 8 blood tests that measure your blood sugar (glucose), electrolyte and fluid balance, and kidney function. It provides critical information about your body's chemical balance and metabolism.
Lipid Panel
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A lipid panel measures the levels of fats (lipids) in your blood, including cholesterol and triglycerides. It is a key tool for assessing your risk of cardiovascular disease, including heart attack and stroke. Regular lipid screening is recommended for all adults.
Hemoglobin A1c (HbA1c)
Endocrinology
The hemoglobin A1c test measures your average blood sugar level over the past 2–3 months. It works by measuring the percentage of hemoglobin (the oxygen-carrying protein in red blood cells) that is coated with sugar (glycated). It is the primary test used to diagnose and monitor diabetes.
Medical Disclaimer
This lab test information is for educational purposes only and should not replace professional medical advice. Lab results should always be interpreted by a qualified healthcare provider who knows your complete medical history. Normal ranges may vary between laboratories.