In the context of blood work, PLT refers to the platelet count. Platelets are the cells that cause blood clotting and control bleeding. The normal range of platelets for adults is 3.5 to 10.5 billion cells per liter of blood, according to the Mayo Clinic.
An abnormal platelet count may indicate an underlying condition such as cancer, bone marrow problems or iron deficiency. Some medications may also affect platelet count.
A complete blood count also includes a count of white and red blood cells. Another blood test that doctors often order is a blood chemistry test. This test measures the other components found in blood, such as enzymes, sugar, electrolytes and lipids.