Adenitis is a general term for an inflammation of a gland. Often it is used to refer to lymphadenitis which is the inflammation of a lymph node.^{[citation needed]}

Lymph adenitis or lymph node adenitis is caused by infection in lymph nodes. The infected lymph nodes typically become enlarged, warm and tender. A swelling of lymph nodes due to growth of lymph cells is called lymphadenopathy. Types include:^{[citation needed]}

Sebaceous adenitis is an inflammation of the sebaceous glands in the skin. These glands normally produce sebum (skin oil, a lipid-rich secretion) which prevents drying of the skin.^{[citation needed]}