A low white blood cell count, called leukopenia, could point to an autoimmune disorder. A low white blood cell count could also be caused by other factors.
Many diseases and disorders can cause a low white blood cell count. Some of these diseases are manageable, while others are more serious. AIDS, hepatitis, leukemia, lupus and aplastic anemia are some disorders that can cause this symptom. Certain medications, such as antihistamines, antibiotics and diuretics, can also make white blood cell production decrease. Because they are typically more susceptible to infection, some patients with a persistent low white blood cell count must take special precautions to prevent getting sick, explains Mayo Clinic. These precautions include washing hands regularly, avoiding people with colds or other illness, and wearing a face mask. Serious complications, such as infections or organ failure, can arise if the problem is not treated quickly.
Doctors order a white blood cell count, along with other tests, to help diagnose illnesses, according to Mayo Clinic. No preparation is usually necessary before a white blood cell count, which is obtained by taking a blood sample from a vein, states MedlinePlus. A normal white blood cell count ranges from 4,500 to 10,000 white blood cells per microliter. Because normal value ranges sometimes differ among laboratories, it's best for patients to discuss individual results with their doctor.