A high monocyte count might be a sign of a chronic infection, an autoimmune disorder or a blood disorder, states Merck Manuals Home Health Handbook. Campbell County Memorial Hospital advises that it might also be a sign of leukemia or a heart infection.
Monocytes are one of five types of white blood cells. The ideal level of monocytes is zero to ten percent of white blood cells, states Campbell County Memorial Hospital.
According to the Medical University of South Carolina, monocyte count and other laboratory tests are ordered when a doctor suspects a disease or infection or to evaluate whether a disease is improving or worsening.