Neck swelling is usually caused by enlarged glands in the neck, specifically the lymph glands, thyroid, and tonsils. The lymph glands and tonsils can be infected by virus or bacteria, such as mononucleosis, strep throat, and upper respiratory infections. The thyroid gland can become diseased or dysfunctional, as in the case of hypothyroidism and hyperthyroidism, and cause swelling. A swollen neck might also be caused by allergies.
A diseased thyroid gland is one of the most common causes of neck swelling. The thyroid gland is located at the lower front region of the neck. Any disease that affects the thyroid gland can result in swelling of the gland and the neck by proximity. Hypothyroidism, which is a failure to produce a sufficient amount of hormones, is one cause of gland swelling. Hyperthyroidism, on the other hand, is an over-production of hormones and can also cause gland and neck swelling.
Neck swelling may also be caused by mononucleosis, also called mono. The swollen appearance and feeling in the neck is caused by swollen lymph glands. The lymph nodes are an important part of the human immune system, and when an infection is present the lymph glands tend to swell up. Mono is an infection caused by the Epstein-Barr virus. Other symptoms of mononucleosis are fever, fatigue, and loss of appetite.
Sore throat is a common cause of neck swelling. A sore throat can be caused by a wide variety of factors. Swelling in the tonsils and the lymph nodes is symptomatic of a sore throat, which may appear as swelling in the neck. Symptoms of a sore throat are pain while swallowing and sharp, dull, or scratching sensations. If tonsillitis is the cause of sore throat, surgery is required to remove the infected tonsils.
A strep throat infection is also a common cause of neck swelling. Strep throat is a bacterial infection, specifically the streptococcus bacteria. The lymph glands and the tonsils both tend to swell when this infection is present. In fact, just about any upper respiratory infection can cause the lymph glands or the tonsils to swell. This is a sign that the immune system is responding to the infection.
Allergies can also cause a swollen neck. The skin itself may produce an allergic reaction, such as a rash, which usually includes some swelling. Food allergies can cause the throat to swell up. Any allergic reaction in the neck region can also cause the lymph glands to swell.
Cancer is a less common cause of neck swelling. Cancerous lymph nodes, as seen in Hodgkin’s disease, may produce a swollen appearance and sensation in the neck. Thyroid cancer also produces swelling in the neck, commonly called a goiter. The swelling is a result of tumors growing in and around the glands.