The most common causes of swollen lymph nodes include a cold, tonsillitis, strep throat, or an ear infection that spreads. Other conditions, including cancer, human immunodeficiency virus (HIV), and mononucleosis, can also cause swollen lymph nodes in the throat, but these conditions are much less common. Swollen lymph nodes respond to treatment with home remedies or antibiotics, and the swelling typically subsides within a couple of weeks.

Several groups of lymph nodes exist throughout the body as part of the human lymphatic system. These clusters of white blood cells, called lymphocytes, play an important role in the immune system: they create antibodies that fight viral and bacterial infections. When the immune system attempts to fight these foreign substances, lymphocytes multiply. If an infection persists, it can spread and might cause swollen lymph nodes in the throat or other areas of the body.

The common cold frequently leads to swollen lymph nodes in the throat, along with discomfort, fever, and runny nose if an upper respiratory infection is involved. The lymph nodes in the neck might feel tender in someone with a cold. Warm compresses and over-the-counter pain relievers may help relieve symptoms.

Strep throat might also lead to swollen lymph nodes in the neck. A person with this condition might have trouble swallowing, a headache, and a stiff neck. Doctors commonly recommend extra fluids and rest, along with antibiotics, to treat strep throat. Gargling with warm salt water helps some patients feel better, as can using numbing sprays to deaden pain. If symptoms last more than four days, medical treatment should be sought.

Lymph nodes in the tonsils might also become inflamed and swollen when infected. These nodes drain fluid to the back part of the throat. Infected tonsils typically appear red and might develop white spots, indicating infection; other symptoms include a change in the voice and bad breath. Mild tonsillitis may not need any special treatment, but if a throat culture indicates a serious infection — such as strep — a medical professional might prescribe antibiotics. Surgical removal of the tonsils might be necessary if tonsillitis becomes chronic.

Lymphomas, which are cancers of the lymphatic system, can cause the lymph nodes to become enlarged; swollen lymph nodes in the throat are a common symptom of both Hodgkin's and non-Hodgkin's lymphomas. Non-Hodgkin's lymphoma, which is actually a group of 16 different diseases, is characterized by night sweats, weight loss, fatigue, and fever. Hodgkin's lymphoma is less common than the non-Hodgkin forms, and has many of the same symptoms. Both forms of cancer can be treated effectively if diagnosed early.

Any disorder that affects the immune system might hinder the body's ability to fight off infection. HIV can lead to frequent infections, causing swollen lymph nodes in the throat or anywhere in the body; it also increases the risk for certain forms of cancer, including lymphomas. Doctors usually prescribe medication to ease symptoms in HIV patients.