Anatomy & Physiology: The Unity of Form and Function, 7th Edition

Published by McGraw-Hill Education
ISBN 10: 0073403717
ISBN 13: 978-0-07340-371-7

Chapter 18 - Section 18.4 - Leukocytes - Before You Go On - Page 696: 20

Answer

An abnormally high or low white blood cell (WBC) count, also known as leukocytosis and leukopenia respectively, can be indicative of various underlying health conditions. These conditions can affect the bone marrow, immune system, or other body systems. Here's an overview of what can cause these abnormalities: **Abnormally High WBC Count (Leukocytosis):** Leukocytosis often indicates an increased demand for white blood cells due to an infection, inflammation, or other medical conditions. Some common causes include: 1. **Infection:** Bacterial, viral, fungal, or parasitic infections can trigger an increase in WBCs as the immune system responds to fight off the pathogens. 2. **Inflammatory Disorders:** Conditions like rheumatoid arthritis, inflammatory bowel disease, and certain autoimmune disorders can cause chronic inflammation, leading to elevated WBC counts. 3. **Tissue Damage or Injury:** Trauma, burns, surgery, and tissue damage can lead to an inflammatory response and higher WBC levels. 4. **Stress:** Physical or emotional stress can cause a temporary increase in WBCs due to the body's "fight or flight" response. 5. **Medications:** Some medications, such as corticosteroids, can lead to leukocytosis as a side effect. 6. **Leukemia or Blood Disorders:** Certain types of leukemia and other blood disorders can result in an excessive production of abnormal white blood cells. 7. **Allergic Reactions:** Severe allergic reactions can trigger an increase in eosinophils and basophils, leading to leukocytosis. 8. **Smoking:** Smoking can cause an increase in white blood cell count due to inflammation and oxidative stress. **Abnormally Low WBC Count (Leukopenia):** Leukopenia can result from a decreased production of white blood cells or increased destruction of them. Some common causes include: 1. **Bone Marrow Disorders:** Conditions like aplastic anemia, myelodysplastic syndrome, and leukemia can lead to reduced WBC production. 2. **Viral Infections:** Certain viral infections, such as HIV, can suppress the immune system and lead to a decrease in WBC count. 3. **Autoimmune Disorders:** Conditions like lupus and rheumatoid arthritis can affect the bone marrow and cause leukopenia. 4. **Medications:** Some medications, such as chemotherapy drugs, can temporarily suppress bone marrow function, leading to leukopenia. 5. **Certain Diseases:** Conditions like Felty syndrome, which is associated with rheumatoid arthritis, can result in low WBC counts. 6. **Malnutrition:** A deficiency of certain nutrients, such as vitamin B12 and folic acid, can impact WBC production. 7. **Radiation Exposure:** High levels of radiation exposure can damage bone marrow and lead to leukopenia. 8. **Sepsis:** Severe sepsis or bloodstream infections can cause a drop in WBC count. It's important to note that abnormal WBC counts are often just a piece of the diagnostic puzzle. A thorough medical evaluation, including clinical history, physical examination, and additional tests, is needed to determine the underlying cause and appropriate treatment. If you have concerns about your WBC count, it's best to consult a healthcare professional.

Work Step by Step

An abnormally high or low white blood cell (WBC) count, also known as leukocytosis and leukopenia respectively, can be indicative of various underlying health conditions. These conditions can affect the bone marrow, immune system, or other body systems. Here's an overview of what can cause these abnormalities: **Abnormally High WBC Count (Leukocytosis):** Leukocytosis often indicates an increased demand for white blood cells due to an infection, inflammation, or other medical conditions. Some common causes include: 1. **Infection:** Bacterial, viral, fungal, or parasitic infections can trigger an increase in WBCs as the immune system responds to fight off the pathogens. 2. **Inflammatory Disorders:** Conditions like rheumatoid arthritis, inflammatory bowel disease, and certain autoimmune disorders can cause chronic inflammation, leading to elevated WBC counts. 3. **Tissue Damage or Injury:** Trauma, burns, surgery, and tissue damage can lead to an inflammatory response and higher WBC levels. 4. **Stress:** Physical or emotional stress can cause a temporary increase in WBCs due to the body's "fight or flight" response. 5. **Medications:** Some medications, such as corticosteroids, can lead to leukocytosis as a side effect. 6. **Leukemia or Blood Disorders:** Certain types of leukemia and other blood disorders can result in an excessive production of abnormal white blood cells. 7. **Allergic Reactions:** Severe allergic reactions can trigger an increase in eosinophils and basophils, leading to leukocytosis. 8. **Smoking:** Smoking can cause an increase in white blood cell count due to inflammation and oxidative stress. **Abnormally Low WBC Count (Leukopenia):** Leukopenia can result from a decreased production of white blood cells or increased destruction of them. Some common causes include: 1. **Bone Marrow Disorders:** Conditions like aplastic anemia, myelodysplastic syndrome, and leukemia can lead to reduced WBC production. 2. **Viral Infections:** Certain viral infections, such as HIV, can suppress the immune system and lead to a decrease in WBC count. 3. **Autoimmune Disorders:** Conditions like lupus and rheumatoid arthritis can affect the bone marrow and cause leukopenia. 4. **Medications:** Some medications, such as chemotherapy drugs, can temporarily suppress bone marrow function, leading to leukopenia. 5. **Certain Diseases:** Conditions like Felty syndrome, which is associated with rheumatoid arthritis, can result in low WBC counts. 6. **Malnutrition:** A deficiency of certain nutrients, such as vitamin B12 and folic acid, can impact WBC production. 7. **Radiation Exposure:** High levels of radiation exposure can damage bone marrow and lead to leukopenia. 8. **Sepsis:** Severe sepsis or bloodstream infections can cause a drop in WBC count. It's important to note that abnormal WBC counts are often just a piece of the diagnostic puzzle. A thorough medical evaluation, including clinical history, physical examination, and additional tests, is needed to determine the underlying cause and appropriate treatment. If you have concerns about your WBC count, it's best to consult a healthcare professional.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.