Finding an enlarged lymph node or nodes, cause many to worry about cancer. Here is an informative discussion about lymph nodes from the Mayo Clinic, about the many causes of enlargement, and when to call your doctor.

Swollen lymph nodes combined with other signs and symptoms are a common reason people, particularly children, visit their doctors. Most often, lymph nodes swell and become inflamed as a result of an infection. However, there are many possible causes of swollen lymph nodes, including autoimmune diseases, such as rheumatoid arthritis, noncancerous (benign) tumors and cancer.

Your lymph nodes, also called glands, play a vital role in your body's ability to fight off viruses, bacteria and other causes of illnesses. Some 600 lymph nodes are situated throughout your body, with the majority in your head and neck. The lymph nodes that most frequently swell are in your neck, under your chin, in your armpits and in your groin. The site of the swollen lymph nodes may help identify the underlying cause.

Treatment for inflamed, swollen lymph nodes, also known as lymphadenitis, depends on the cause. In some cases, over-the-counter (OTC) pain relievers and warm compresses may be all you need. For more serious cases, treatment of swollen lymph nodes involves treating the underlying cause.

Causes

The most common cause of swollen lymph nodes is an infection, particularly viral infections such as the common cold. However, there are other types of infection, including parasitic and bacterial, and other possible swollen lymph node causes. They include:

Common infections

Strep throat

Mumps

Measles

Ear infections

Infected (abscessed) tooth

Mononucleosis

Wound infections

Other infections

Tuberculosis

Certain sexually transmitted diseases, such as syphilis

Toxoplasmosis — a parasitic infection resulting from contact with the feces of an infected cat or eating undercooked meat

Cat scratch fever — a bacterial infection from a cat scratch or bite

Immune system disorders

Lupus — a chronic inflammatory disease that can target your joints, skin, kidneys, blood cells, heart and lungs

Rheumatoid arthritis — a chronic inflammatory disease that targets the tissue that lines your joints (synovium)

Human immunodeficiency virus (HIV) — the virus that causes AIDS

Cancers

Lymphoma — cancer that originates in your lymphatic system

Leukemia — cancer of your body's blood-forming tissue, including your bone marrow and lymphatic system

Other possible but rare causes include certain medications, such as phenytoin (Dilantin), used to prevent seizures, and certain immunizations, such as for malaria.

When to seek medical advice

Some swollen lymph nodes return to normal when the underlying condition, such as a cold, resolves. However, see your doctor if you're concerned or if your swollen lymph nodes:

Have appeared for no apparent reason

Continue to enlarge

Feel hard or fixed

Are accompanied by fever, night sweats or unexplained weight loss

Are red, warm and tender