Lymph Node Under the Jaw: Why It Becomes Inflamed and What It Means

In the morning you run your hand along your neck and feel a small, tender lump under your jaw. This happens often and usually resolves on its own, but it is still worth understanding what exactly has become inflamed.

Where the lymph nodes under the jaw are located and why they are needed

Lymph nodes are part of the immune system: they help the body recognize and fight off infections and foreign substances. There are about 600 lymph nodes in the human body, but normally only some can be felt — the submandibular, axillary, and inguinal ones. Under the jaw and chin, behind the ears, and on the back of the head, lymph nodes form chains that collect lymph from the oral cavity, teeth, gums, throat, and scalp. When an infection appears nearby, the nearest node enlarges to fight it more actively. In most cases, a normal lymph node size is considered to be no more than 1 cm in diameter.

Why the lymph node under the jaw becomes inflamed

Infections are the most common cause of enlarged lymph nodes. These include a dental abscess or an impacted (unerupted) tooth, otitis, a cold, influenza and other infections, gum inflammation, mononucleosis, stomatitis, tonsillitis, tuberculosis, skin infections, and sexually transmitted infections. Less common are immune and autoimmune causes (HIV, rheumatoid arthritis), certain medications, and malignant diseases — leukemia, lymphoma, and other tumors. Slow and painless enlargement is sometimes associated with a tumor, while sudden and painful enlargement is usually associated with trauma or infection. Colds, tonsillitis, and ear or throat infections are frequent culprits; viral infections such as glandular fever — sometimes; something more serious — rarely.

Submandibular lymphadenitis: how it manifests

Submandibular lymphadenitis begins with painful enlargement of the node. Pain appears due to rapid stretching of the capsule; it also occurs with suppuration. Enlarged nodes feel like tender bumps on the sides of the neck under the chin. Sore throat, cough, high fever, night sweats, weight loss, and prolonged fever may be added. On examination, the doctor notes the size, tenderness, consistency, adherence of the nodes to each other, and location. Soft nodes are more often associated with infection, firm elastic ones are suspicious for lymphoma, and stone-hard ones for cancerous involvement. The presence or absence of pain alone does not distinguish a benign from a malignant process.

The lymph node under the chin and between the jaw and ear

The lymph nodes under the chin and between the jaw and ear collect lymph from adjacent areas, so they react to problems in the mouth, teeth, ears, and scalp. If the lymph node between the jaw and ear has become inflamed, recall whether there has recently been otitis, stomatitis, or a skin infection nearby.

How the doctor determines the cause of lymph node enlargement

The doctor performs a physical examination and asks about the medical history and symptoms: when the enlargement began, whether it was sudden, and whether it is tender when pressed. The doctor palpates the submandibular, anterior and posterior cervical, supraclavicular, axillary, and inguinal nodes so as not to miss generalized lymphadenopathy: on initial examination it is detected in only 17% of patients. With localized enlargement, the areas from which lymph drains to these nodes are examined. Blood tests may be ordered, including liver and kidney panels and a complete blood count with a leukocyte differential, lymph node biopsy, chest X-ray, and CT of the chest and abdomen. Treatment depends on the cause.

When an enlarged lymph node requires urgent medical attention

You should see a doctor if the nodes are enlarging or do not shrink within a week, have become hard or do not move when pressed, night sweats or very high fever have appeared, there are no other signs of illness, or the nodes above or below the collarbone are enlarged. In children, any node larger than 1 cm is a reason for examination. Enlarged nodes caused by infection usually resolve on their own within 1–2 weeks.

• The node is growing or has not shrunk for more than a week
• The node is hard, irregular, or does not move
• Night sweats or very high fever
• Enlarged nodes above or below the collarbone
• In a child, any node larger than 1 cm

Enlargement of a lymph node under the jaw is not in itself a reason to call an ambulance. Call 103 or 112 if severe difficulty swallowing or breathing occurs.

This material is for reference: it helps you get your bearings but does not replace a consultation with a doctor, who will examine you and determine the cause.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer