Cervical lymph nodes are part of the lymphatic system, which includes vessels, tissues, and organs that help to regulate the body's fluid balance and fight infections. It is the job of this system to drain excess fluid, called lymph, from the tissues and return it to the circulation blood. The cervical lymph nodes, of which there are about 300, are located in the neck. They are classified in a number of different ways, largely based on their location.

Lymph is clear in color and consists of proteins taken from the blood. This fluid drains out of the lymph capillaries. These are thin-walled blood vessels that are closed at one end and are located in the spaces between cells throughout the body.

There are many illnesses and diseases that affect the cervical lymph nodes. Some of these, like strep throat and tonsillitis, are relatively common. More serious illness include lymphadenopathy, lymphoma, and mononucleosis.

Lymphadenopathy is a term for swollen or enlarged lymph nodes. This condition is more common in children than adults. There are many different reason a patient can have swollen nodes, including an infection, and it can be difficult to diagnose an underlying cause. In many cases, the nodes will return to normal within two weeks; when swelling persists, an individual should see a doctor so that a diagnosis can be made.

One cause of swollen lymph nodes is mononucleosis. Mononucleosis, also known as "mono" or the "kissing disease," is caused by the Epstein-Barr virus. It can be spread by saliva, often exchanged by drinking from an infected person's drinking glass or utensils, coughing, sneezing, and kissing. Often, it is spread by people who do not show any symptoms. It is more common in pre-teens and young adults, but young children can get it by touching a toy with saliva on it.

Lymphoma is a type of cancer that affects the lymphatic system. One of the first symptoms is swollen armpit, groin, or cervical lymph nodes. Lymphoma falls into two general categories: Hodgkin disease and Non-Hodgkin lymphoma.

Hodgkin disease, of which there are several types, involves a specific type of abnormal lymphocyte, called Reed-Sternberg cells. Non-Hodgkin lymphoma also affects the lymphocytes, but does not involve the development of Reed-Sternberg cells. There are many different types of Non-Hodgkin lymphoma, depending on which lymphocytes are affected, the size of the cancer cells, cell growth pattern, and other factors.

The cervical lymph nodes are great indicators of illness. Regular check-ups can help catch many ailments early. Early detection can often give patients the best possible outcome of the diseases or viruses that affect them.