Lymphoid hyperplasia is an increase in the number of normal cells (called lymphocytes) that are contained in lymph nodes. This most often happens when there is an infection with bacteria, viruses, or other types of germs and is part of the body's reaction to the infection.
Update Date 9/10/2015
Updated by: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.