Mean Corpuscular Volume (MCV) Lab Values
Included In This Lesson
Study Tools For Mean Corpuscular Volume (MCV) Lab Values
Outline
Objective:
Determine the significance and clinical use of Mean Corpuscular Volume lab value in clinical practice
Lab Test Name:
Mean Corpuscular Volume
Description:
Provides a measure of the RBC volume averaged over millions of cells
MCV:
- Average size volume of individual RBCs
- Determination of etiology of anemia
Indications:
Determining etiology of anemia:
- Iron-deficient anemia
- Pernicious anemia- B12 deficiency
- Folic acid deficient anemia
- Aplastic anemia- deficiency of all blood cell types
Normal Therapeutic Values:
Normal – 80-100 fL
Collection:
- CBC
- Lavender tube
What would cause increased levels?
Elevated MCV: >100 fL
- Macrocytosis- larger than normal RBCs
- Folate/Vitamin B12 deficiency
- Megaloblastic anemia
- Reticulocytosis
What would cause decreased levels?
Low MCV:<80 fL
- Microcytosis- a defect in hemoglobin synthesis resulting in smaller than normal RBCs
- Iron deficiency anemia
- Thalassemia- genetic disorder in which there is less hemoglobin in the body
Transcript
Hey everyone, Abby here with nursing.com. This lesson covers MCV or mean corpuscular volume. We’ll talk about the normal values and situations in which this lab would be increased or decreased. Let’s get started.
mean corpuscular volume abbreviated as MCV measures the red blood cell volume averaged over millions of cells. Remember, the mean is an average. Now, the average size and volume of individual red blood cells is measured with this lab, but it also defines the etiology of anemia. So, we can determine, is it an iron deficiency? Is it B12 or folate? It helps us to see. Now, how it’s calculated, the MCV measured in femtoliters, is equal to 10 times the hematocrit value, divided by the red blood cell count.
Now, when do you think we would have this test run? What would indicate it? Well, you already talked about anemia, right? Yeah. Kind of spoiled the surprise. It helps us to determine what the cause of the anemia is or what type. So, as mentioned, it could be iron deficiency, it could be a B12 or folate deficiency. It also could be just full blown bone marrow suppression, no red blood cells or other blood products. As you can see here, it’s measured on a CBC. It’s collected in a lavender tube. Normal values are between 80 and a hundred femtoliters. When non values are increased, that means that they’re above a hundred femtoliters. That indicates that there’s macrocytosis going on, or the red blood cells are larger than normal and that is a folate or vitamin B12 deficiency. We know that the vitamin B12 deficiency is our pernicious anemia, right? It could also be that the red blood cells are huge <laugh> megaloblastic anemia. It could also be in the case of an elevation in reticulocytes or young red blood cells, and this is just a sign that there’s an unusually rapid, really rapid request from the bone marrow to produce red blood cells.
It will be decreased or below 80 femtoliters in microcytosis, or smaller than normal red blood cells. This is going to be the case in iron deficient anemia and a rare blood disorder, Thalassemia. Now, look at these images. You can see this is macrocytic and this is microcytic. That’s when we see the difference in lab values, let’s take a look at our linchpins.
The mean corpuscular volume MCV lab measures the average size of red blood cells. They should range in size between 80 and a hundred femtoliters. If it’s bigger than that, the red blood cells are huge and that is going to indicate a B12 or folate deficiency. If they’re small or really tiny red blood cells, we have an iron deficiency, therefore not allowing for those red cells to be formed as easily. And remember, as is typical in nursing and in general, these are labs that are never going to be used on their own for diagnosis. Keep in mind that big picture, right? Our patient has a lot going on.
Well done. Everyone now go out and be your best self today and happy nursing.
References:
- https://www.sciencedirect.com/topics/medicine-and-dentistry/carboxyhemoglobin
- https://www.ncbi.nlm.nih.gov/books/NBK545275/#:~:text=Introduction,divided%20by%20the%20erythrocyte%20count
- https://www.uptodate.com/contents/diagnostic-approach-to-anemia-in-adults?search=MCV%20lab§ionRank=1&usage_type=default&anchor=H3977622663&source=machineLearning&selectedTitle=1~80&display_rank=1#H3977622663
- https://medlineplus.gov/lab-tests/mcv-mean-corpuscular-volume/
Rina’s NCLEX Study Plan 2026
Concepts Covered:
- Endocrine System
- Studying
- Urinary System
- Tissues and Glands
- Nervous System
- Circulatory System
- Medication Administration
- Hematologic System
- Skeletal System
- Digestive System
- Respiratory System
- Emergency Care of the Cardiac Patient
- Reproductive System
- Endocrine and Metabolic Disorders
- Basics of Human Biology
- Muscular System
- Sensory System
- Communication
- Legal and Ethical Issues
- Basics of NCLEX
- Prenatal Concepts
- Prioritization
- Fundamentals of Emergency Nursing
- Documentation and Communication
- Delegation
- Community Health Overview
- Factors Influencing Community Health
- Concepts of Mental Health
- Test Taking Strategies
- Note Taking
- Substance Abuse Disorders
- Behavior
- Concepts of Population Health
- Concepts of Pharmacology
- Health & Stress
- Labor and Delivery
- Gastrointestinal Disorders
- Microbiology
- Depressive Disorders
- Postpartum Care
- Emergency Care of the Trauma Patient
- Emotions and Motivation
- Growth & Development
- Intelligence and Language
- Psychological Disorders
- State of Consciousness
- Respiratory Disorders
- EENT Disorders
- Infectious Disease Disorders
- Integumentary Disorders
- Neurologic and Cognitive Disorders
- Hematologic Disorders
- Cardiovascular Disorders
- Musculoskeletal Disorders
- Renal and Urinary Disorders
- Oncologic Disorders
- Anxiety Disorders
- Cognitive Disorders
- Eating Disorders
- Personality Disorders
- Psychotic Disorders
- Trauma-Stress Disorders
- Bipolar Disorders
- Developmental Considerations
- Psychological Emergencies
- Somatoform Disorders
- Perioperative Nursing Roles
- Preoperative Nursing
- Central Nervous System Disorders – Brain
- Lower GI Disorders
- Peripheral Nervous System Disorders
- Cardiac Disorders
- Integumentary Disorders
- Musculoskeletal Disorders
- Noninfectious Respiratory Disorder
- Postoperative Nursing
- Respiratory Emergencies
- Intraoperative Nursing
- Disorders of Pancreas
- Urinary Disorders
- Neurological Emergencies
- Central Nervous System Disorders – Spinal Cord
- Renal Disorders
- Infectious Respiratory Disorder
- Sexually Transmitted Infections
- EENT Disorders
- Shock
- Cardiovascular
- Shock
- Disorders of the Posterior Pituitary Gland
- Endocrine
- Disorders of the Thyroid & Parathyroid Glands
- Gastrointestinal
- Upper GI Disorders
- Liver & Gallbladder Disorders
- Neurological
- Respiratory
- Hematologic Disorders
- Acute & Chronic Renal Disorders
- Disorders of the Adrenal Gland
- Immunological Disorders
- Oncology Disorders
- Female Reproductive Disorders
- Musculoskeletal Trauma
- Vascular Disorders
- Male Reproductive Disorders
- Newborn Complications
- Disorders of Thermoregulation
- Neurological Trauma
- Integumentary Important Points
- Multisystem
- Emergency Care of the Neurological Patient
- Emergency Care of the Respiratory Patient
- Prefixes
- Suffixes
- Fetal Development
- Terminology
- Proteins
- Statistics
- Med Term Basic
- Med Term Whole
- Basics of Mathematics
- Basics of Sociology
- Pregnancy Risks
- Labor Complications
- Newborn Care
- Postpartum Complications
- Understanding Society
- Adult
- Dosage Calculations
- Adulthood Growth and Development
- Learning Pharmacology