Normal Results

• According to many medical encyclopedias, such as the Medline Plus reference provided by the National Library of Medicine, a normal WBC count lies somewhere between 4,500-10,000 white blood cells per mcl of blood. However, this number can vary from physician to physician.
  
  

Chemical Reasons

• Crystal meth use affects your WBC count
  
  A high WBC count can have chemical causes such as smoking cigarettes or taking certain medications. Medications that affect a person's WBC count include corticosteroids and epinephrine-based drugs. Illicit drug use can also cause a blood high WBC count. One illegal drug that is known to cause abnormal changes in white blood cells is methamphetamine, also known as crystal meth.
  
  

Leukemia

• Hairy Cell leukemia can cause high WBC counts
  
  A high WBC count can be indicative of several strains of leukemia such as acute lymphocytic leukemia, chronic lymphocytic leukemia, acute myelogenous leukemia and hairy cell leukemia. A visit with your physician will help determine whether your results are due to these conditions.
  
  

Allergies and Stress

• High levels of stress and anxiety can affect a person's WBC count. Extreme bouts of depression or recent traumatic experiences can cause the white blood cells to work overtime. Severe allergic reactions can also cause a spike in white blood cell production.
  
  

Myelofibrosis

• Myelofibrosis is a bone marrow disorder that interferes with the body's production of blood cells. This results in stunted growth and scarring of the bone marrow. This is a serious disease that mainly affects people over the age of fifty but can occur in people of any age.
  
  

Respiratory Conditions

• A high WBC count can be caused by respiratory conditions such as pneumonia, whooping cough and tuberculosis. If tuberculosis is suspected, a skin patch test will be done to rule it out or confirm it. Antibiotics cure many of these conditions.
  
  

Other Causes

• Because white blood cells are responsible for helping the immune system work, when an infection or foreign bacteria is present, there will be an increase in white blood cells. It is important to schedule appointments with your physician to determine the possible causes of your irregular WBC count. Measles, anemia, burns and even sexually transmitted infections can cause high and low WBC counts.