Thanks for writing to the forum!
Severe dehydration can cause a high cell count. Another possibility is myeloproliferative disorders of the bone marrow.
Myeloproliferative disorders include:
• Polycythemia vera -- occurs when the bone marrow produces too many blood cells, especially red blood cells
• Essential thrombocytosis -- occurs when the body produces too many platelet cells, which help blood to clot. Clots can block blood vessels leading to heart attack or stroke.
• Primary or idiopathic myelofibrosis (also known as myelosclerosis) -- occurs when the bone marrow produces too much collagen or fibrous tissue in the bone marrow. This reduces bone marrow's ability to produce blood cells.
• Chronic myelogenous leukemia (CML) -- cancer of the bone marrow that produces abnormal granulocytes (a type of white blood cell) in the bone marrow
It is difficult to comment beyond this at this stage. Wait for the results. If the high values persist consult a hematologist ASAP. Please let me know if there is any thing else and do keep me posted. Take care!