Lymph nodes produce immune cells to help fight infection. They also filter the lymph fluid and remove foreign material, such as bacteria and cancer cells. They can become swollen from inflammatory conditions, an abscess, cancer, and most commonly from infection. Common areas where lymph nodes can be felt include the groin, armpit, behind the ears, back of the head, sides of the neck and under the jaw and chin.
Reviewed By: Laura J. Martin, MD, MPH, ABIM Board Certified in Internal Medicine and Hospice and Palliative Medicine, Atlanta, GA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.