What Are High Monocytes?

The normal range for monocytes in white blood cells is 2 to 8 percent; any result higher than 8 is considered abnormal, notes MedlinePlus. Monocytes are one of the five types of white blood cells that normally appear in the blood.

An increased percentage of monocytes can be an indication of several health conditions, explains MedlinePlus. It might also be increased due to the decrease in one of the other four types of cells. The most common reasons for a high level of monocytes are chronic inflammatory disease, leukemia, parasitic infection and tuberculosis. Another common cause for a high level of monocytes is a viral infection, such as infectious mononucleosis, mumps and measles.

Monocytes within white blood cells are fewer than neutrophils and lymphocytes, states MedlinePlus. The normal range for neutrophils is 40 to 60 percent, while the range for lymphocytes is 20 to 40 percent. The other two types of white blood cells are the eosinophils and basophils; together these cells should not be more than 5 percent of the white blood cells. One other type of cell, band, is considered a young neutrophil and may not be present at all, but is typically no more than 3 percent.