MultiCare Health System

• MultiCare Regional Cancer
  Center
• The Dr. Richard C.
  Ostenson Cancer Center
• Types of Cancer
• Patient Resources
• Find a Location
• Cancer Care Guide
  • The Healing Environment
  • Understanding Cancer
  • Wellness and Support
    Services
  • Keeping Track of My Care
    • Keeping Lab Results
    • Key Terms
       
    • Communicating With Your
      Health Care Team
    • Asking the Right Questions
    • My Care Plan
    • Journaling
    • Goal Setting
     
  • The Caregivers
  • Managing Your Symptoms and
    Improving Your Health
  • Cancer Services and
    Resouces
  • Legal Considerations
  • Comfort Care
  • Glossary of Cancer Related
    Terms
   
 

Key Terms

White blood cell (WBC) count. White blood cells protect the body against infection. If an infection develops, white blood cells attack and destroy the bacteria, virus, or other organism causing it. White blood cells are bigger than red blood cells and normally fewer in number. When a person has a bacterial infection, the number of white cells can increase dramatically. The white blood cell count shows the number of white blood cells in a sample of blood. The number of white blood cells is sometimes used to identify an infection or to monitor the body’s response to cancer treatment.

White blood cell types (WBC differential). There are five major kinds of white blood cells: neutrophils, lymphocytes, monocytes, eosinophils, and basophils. Immature neutrophils, called band neutrophils, are also included and counted as part of this test. Each type of cell plays a different role in protecting the body. The numbers of each one of these types of white blood cells give important information about the immune system. An increase or decrease in the numbers of the different types of white blood cells can help identify infection, an allergic or toxic reaction to certain medications or chemicals, and many conditions (such as leukemia).
 
Red blood cell (RBC) count. Red blood cells carry oxygen from the lungs to the rest of the body. They also help carry carbon dioxide back to the lungs so it can be exhaled. The red blood cell count shows the number of red blood cells in a sample of blood. If the RBC count is low, the body may not be getting the oxygen it needs. If the count is too high (a condition called polycythemia), there is a risk that the red blood cells will clump together and block tiny blood vessels.

Hematocrit (HCT, packed cell volume, PCV). This test measures the amount of space (volume) red blood cells occupy in the blood. The value is given as a percentage of red blood cells in a volume of blood. For example, a hematocrit of 38 means that 38% of the blood’s volume is composed of red cells.
 
Hemoglobin (Hgb). Hemoglobin is the major substance in red blood cells. It carries oxygen and gives the blood cell its red color. The hemoglobin test measures the amount of hemoglobin in blood and is a good indication of the blood’s ability to carry oxygen throughout the body.
 
Platelet (thrombocyte) count. Platelets (thrombocytes) are the smallest type of blood cell. They play a major role in blood clotting. When bleeding occurs, the platelets swell, clump together, and form a sticky plug that helps stop the bleeding. If there are too few platelets, uncontrolled bleeding may be a problem. If there are too many platelets, there is a risk of a blood clot forming in a blood vessel. Also, platelets may be involved in hardening of the arteries, or atherosclerosis.