Possible Causes for Swollen Neck Lymph Nodes (2025)

The most common cause of swollen lymph nodes in the neck is a viral infection such as the common cold. Bacterial infections that can cause swollen neck lymph nodes include an infected tooth and strep throat. Immune system disorders and some types of cancer can also lead to swollen neck lymph nodes.

The more common infectious causes of swollen neck lymph nodes include viral and bacterial infections. Left untreated, some of these diseases can lead to serious complications and secondary illnesses. Infections that commonly cause swollen neck lymph nodes include:

• Common cold (viral respiratory infection)

• Ear infection

• Infected tooth (abscessed tooth)

• Influenza (flu)

• Measles (contagious viral infection also known as rubeola)

• German measles (contagious viral infection also known as rubella)

• Mononucleosis (viral infection)

• Mumps (viral infection that affects the salivary glands in the neck)

• Strep throat (bacterial throat infection)

• Tonsillitis (inflammation of the tonsils in the back of the throat)

Less common, but potentially life-threatening infectious diseases that cause swollen neck lymph nodes include:

• AIDS (caused by HIV infection)

• Cat scratch fever (bacterial infection from being scratched or bitten by a cat that carries the bacteria)

• Cellulitis (bacterial skin infection)

• Infected wound

• Syphilis (sexually transmitted disease caused by bacteria)

• Toxoplasmosis (parasitic infection)

• Tuberculosis (serious infection affecting the lungs and other organs)

Swollen neck lymph nodes can also be caused by noninfectious disorders such as:

• Chronic fatigue syndrome

• Lymphatic obstruction (blockage in the lymph system)

Swollen neck lymph nodes can also be caused by problems with the immune system itself, such as:

• Juvenile rheumatoid arthritis

• Rheumatoid arthritis (chronic autoimmune disease characterized by joint inflammation)

• Systemic lupus erythematosus (disorder in which the body attacks its own healthy cells and tissues)

The most notable life-threatening diseases that cause swollen neck lymph nodes are different types of cancers including:

• Hodgkin lymphoma (Hodgkin’s disease)

• Leukemia

• Metastasized cancer that has traveled to the lymph nodes

• Non-Hodgkin lymphoma

• Oral, mouth or larynx cancer

Viral infections that cause swollen neck lymph nodes can often be treated with self-care measures at home and the swelling will go away as your body fights off the infection. Self-care measures include rest, drinking plenty of fluids, warm compresses, and over-the-counter pain relievers.

For persistent or chronic swelling, redness and pain, it is important to seek medical care because these are symptoms of a possible bacterial infection. Bacterial infections will need to be treated with antibiotics and a treatment plan designed by your doctor. Left untreated, a localized bacterial infection can spread to the blood and quickly become life threatening. In addition, untreated or poorly controlled lymphoma, leukemia, and other cancers can spread and lead to loss of life.

Over time, untreated and/or undiagnosed swollen neck lymph nodes can lead to serious complications including:

• Formation of an abscess

• Rheumatic fever (inflammatory disease that can develop as a complication of strep throat)

• Scarlet fever (rash caused by strep infections)

• Spread of cancer

• Spread of infection to the blood (septicemia or bacteremia)

• Toxic shock syndrome