Lymphocytosis

A lymphocytosis is an increase in the number of lymphocytes[?] in the blood.

This is common in acute viral infections, including glandular fever.

It may also be seen with intracellular bacterial[?] infections, such as in tuberculosis.

The malignant blood disease chronic lymphocytic leukaemia[?] can cause a massive lymphocytosis, as can other leukaemias.