Bleeding Problems

• A person who has a persistent bleeding problem, such as a chronic bleeding stomach ulcer, will have a lower number of platelets.
  
  

Autoimmune Disorders

• Platelets are destroyed by disorders that attack the organs. For example, an immune system of someone will lupus will manufacture antibodies that attack organs.
  
  

Medications

• Certain medications and drugs can decrease your count. Acetaminophen and Valium are two of the most common such medications. A person undergoing radiation treatment also will have a lower count.
  
  

Bone Marrow

• Any disease that affects the natural production of platelets by bone marrow can mean a lower count. Examples include leukemia, anemia and viral infections like HIV.
  
  

Pregnancy

• During pregnancy, a woman can experience a drop in platelet production. It is estimated that approximately 5 percent of all mothers will have thrombocytopenia while pregnant.