White blood cells are manufactured in bone marrow — the spongy tissue inside some of your larger bones. A low white blood cell count usually is caused by:

  1. Viral infections that temporarily disrupt the work of bone marrow
  2. Certain disorders present at birth (congenital) that involve diminished bone marrow function
  3. Cancer (or other diseases that damage bone marrow)
  4. Autoimmune disorders that destroy white blood cells or bone marrow cells
  5. Severe infections that use up white blood cells faster than they can be produced
  6. Medications, such as antibiotics, that destroy white blood cells
  7. Sarcoidosis

Specific causes of a low white blood cell count include:

  1. Aplastic anemia
  2. Chemotherapy
  3. Radiation therapy
  5. Hypersplenism — a premature destruction of blood cells by the spleen
  6. Tuberculosis (and other infectious diseases)
  7. Kostmann's syndrome — a congenital disorder involving low production of neutrophils
  8. Leukemia
  9. Lupus
  10. Rheumatoid arthritis and other autoimmune disorders
  11. Malnutrition and vitamin deficiencies
  12. Myelodysplastic syndromes
  13. Myelokathexis — a congenital disorder involving failure of neutrophils to enter the bloodstream

Causes shown here are commonly associated with this symptom. Work with your doctor or other health care professional for an accurate diagnosis.

Jan. 23, 2016