A swollen feeling in your neck usually comes from enlarged lymph nodes fighting off an infection, but it can also stem from your thyroid gland, salivary glands, or other structures depending on exactly where the swelling is. The most common cause is a viral infection like the common cold, and in most cases the swelling resolves on its own within a few weeks. That said, the location, size, and texture of the swelling all matter when figuring out what’s going on.
Where the Swelling Is Matters
Your neck contains dozens of lymph nodes, several glands, and a variety of muscles and connective tissue. Swelling in different zones points toward different causes. Midline swelling, right at the front center of your neck below the Adam’s apple, is most often related to the thyroid gland. Swelling along the sides of your neck, particularly along the large muscle that runs from behind your ear to your collarbone, typically involves lymph nodes or salivary glands. Swelling just below and in front of your ear usually involves the parotid gland, while swelling under your jawline may involve the submandibular glands.
Posterior neck swelling, meaning behind or alongside the large neck muscles toward the back, involves a separate group of lymph nodes. This area is sometimes associated with specific infections like toxoplasmosis, which often shows up as a single enlarged node in that region.
Swollen Lymph Nodes From Infection
This is by far the most common reason your neck feels swollen. You have clusters of lymph nodes on both sides of your neck, and they enlarge when your immune system is actively fighting something off. Common triggers include the cold, flu, strep throat, ear infections, and infected teeth. The nodes typically feel like soft, tender, marble-sized bumps that move when you press on them.
Some infections cause more widespread or persistent lymph node swelling. Mononucleosis (caused by the Epstein-Barr virus) and HIV can both cause nodes throughout the neck to enlarge and stay swollen for weeks or longer. Measles and mumps are less common today but still cause noticeable neck swelling in unvaccinated individuals.
Most swollen lymph nodes from infection shrink back to normal within four to six weeks. If a node hasn’t decreased in size after that window, further evaluation is typically warranted.
Thyroid-Related Swelling
The thyroid gland sits at the base of your neck, just below the Adam’s apple, shaped like a butterfly. When it enlarges, the condition is called a goiter. This can involve the entire gland growing uniformly, or one or more lumps (nodules) forming within it. Many goiters are small enough that you can’t see or feel them, and they’re only caught during a routine exam or imaging for something else.
If the thyroid is underactive, you might also notice fatigue, dry skin, feeling cold all the time, constipation, muscle weakness, and trouble concentrating. If it’s overactive, the picture flips: weight loss, rapid heartbeat, excess sweating, sensitivity to heat, tremors, irritability, and difficulty sleeping.
A goiter that grows large enough can press on your airway or voice box, causing difficulty swallowing, a hoarse voice, coughing, snoring, or feeling short of breath during physical activity. If you notice swelling specifically in the lower front of your neck accompanied by any of these symptoms, the thyroid is a likely culprit.
Salivary Gland Problems
Your salivary glands can swell when they become infected or blocked. The condition, called sialadenitis, causes painful swelling in the cheek and neck area along with a dry-feeling mouth. Bacterial infections are the most common cause, with staph bacteria being the usual offender. Viral infections like mumps and flu can also trigger it.
Salivary stones are another frequent cause. These small, hard deposits form inside the gland’s drainage duct and block saliva from flowing out, leading the gland to swell. The swelling often gets worse right before or during meals, when saliva production ramps up but has nowhere to go. You’ll typically feel this swelling just below and in front of your ear (parotid gland) or under your jaw (submandibular gland).
The autoimmune condition Sjögren’s syndrome can also damage salivary glands, causing chronic swelling along with dry mouth and dry eyes. Untreated salivary gland infections can spread to deeper neck tissues, so persistent or worsening swelling in these areas deserves medical attention.
Autoimmune and Systemic Causes
Conditions that involve the immune system attacking the body’s own tissues can cause chronic or recurring neck swelling. Lupus and rheumatoid arthritis are two well-known examples. In these cases, the lymph nodes enlarge not because of an outside infection but because the immune system is in a state of constant overactivity. The swelling tends to be more diffuse, often involving nodes in multiple areas of the body, and it comes alongside other systemic symptoms like joint pain, fatigue, or skin changes.
Congenital Cysts
Some people have small, fluid-filled sacs in their neck that formed before birth and only become noticeable later in life. Branchial cleft cysts are the most common type, appearing on one or both sides of the neck along the main neck muscle. They result from tissues that didn’t develop correctly during fetal growth, leaving empty spaces that fill with fluid. These cysts are almost always benign. They might stay the same size for years or gradually grow larger. Second branchial cleft cysts, located under the skin of the neck muscles on either side, account for 40% to 95% of all cases.
Thyroglossal duct cysts are another congenital type, appearing in the midline of the neck. A characteristic feature is that they move upward when you swallow, because they’re connected to structures near the hyoid bone in your throat.
Signs That Need Prompt Evaluation
Most neck swelling is harmless, but certain features raise the level of concern. A neck mass that has been present for more than two weeks should be evaluated. Lumps larger than about 1.5 centimeters (roughly the width of a nickel) are more likely to need investigation. A mass that feels hard, doesn’t move when you push on it, or has skin changes over it warrants closer attention, since fixed, firm masses are more concerning for malignancy than soft, mobile ones.
Other red flags include a recent voice change, difficulty or pain when swallowing, ear pain on the same side as the lump, unexplained weight loss, or loss of appetite. Any combination of these symptoms alongside a neck mass should prompt a visit to your doctor sooner rather than later.
How Neck Swelling Is Evaluated
A physical exam is the starting point. Your doctor will feel the lump, note its size and location, check whether it moves, and assess its firmness. Blood tests can help identify infections, thyroid dysfunction, or inflammatory markers suggesting an autoimmune process.
Ultrasound is the most common imaging tool for neck lumps. It uses sound waves to create a picture of the area and can distinguish between solid masses and fluid-filled cysts. If the ultrasound shows something abnormal, a biopsy can be performed at the same time, using the ultrasound image to guide a needle into the node or mass. The tissue sample is then examined under a microscope. In some cases, a CT scan may be used instead of or alongside ultrasound to get a more detailed view of deeper structures.