Normal platelets count of a healthy person is 150,000 to 450,000 . Some types of anemia, Viral infections can cause low production of platelets. Some conditions can cause your body to use up or destroy platelets more rapidly than they're produced. This leads to a shortage of platelets in your bloodstream may be due to some bacterial infection. Certain medications also  can reduce the number of platelets in your blood. so detailed history is important for the diagnosis.