Lymph nodes are tiny structures that help the body filter harmful and unhealthy substances, especially those that lead to infection. Cancer.org explains that each lymph node is packed with immune cells that help the body fight off infections by attacking germs carried to the nodes through lymph fluid.
The human body houses hundreds of lymph nodes. Each node provides localized support to that part of the body. For example, lymph fluid in the hands is filtered through nodes in the elbows and armpits. After the fluid has been cleaned by the nodes, it flows back into the bloodstream along with beneficial proteins and salts.
Some nodes are found deep in the abdominal cavity while others are closer to the skin. Cancer.org states that nodes in shallow areas, such as those found near the ears and throat, may feel swollen when the body is fighting off cancer or an infection. Feeling these nodes can provide an advance warning that something is wrong. WebMD explains that swelling is sometimes caused by something innocuous such as a tattoo or insect bite.
Most of the time, the nodes are only swollen in one area. Generalized lymphadenopathy describes a condition in which several areas of the body have swollen nodes. Infections such as chicken pox, immune disorders and some cancers can cause generalized lymphadenopathy, according to Cancer.org.