A lump on the side of your neck with no pain can have many causes. Most commonly, lymph nodes are apt to swell due to injury, infection and, less commonly, cancer.

Published: September 14, 2023 | Updated: June 28, 2024

A painless lump on the side of your neck can have many causes. Most commonly, lymph nodes in your neck are apt to swell due to injury or infection. Less commonly, it can be cancer.

Lymph nodes, part of the immune system, can swell as white blood cells in the lymphatic fluid attack invasive cells. Typically, there are other symptoms, such as fever, that would suggest an infection is causing the swelling. Infections will also often cause painful swelling of the neck. 

If you have a painless lump on the side of your neck, you shouldn’t take the condition lightly. But it’s important to remember that the cause of the lump is often something other than cancer.

As people age, especially those who use tobacco — including cigarettes, cigars, chew or snuff — or who drink alcohol excessively are at higher risk of developing head and neck cancer.

“Benign causes of a painless mass or neck swelling can include thyroid nodules, swelling of a saliva gland, or a reactive lymph node,” said Mia Jusufbegovic, M.D., head and neck surgical oncologist with the Norton Cancer Institute Head & Neck Tumor Program. “However, it is important to rule out cancer as a cause, especially as HPV associated cancers, which are seen in younger patients, are becoming more common. Any persistent neck swelling should be taken seriously and discussed with your primary care provider or ENT.”

As the incidence of HPV related oropharyngeal cancers increases, it is important to eliminate this as a source of a new neck mass, and this often involves performing a biopsy. These cancers are caused the human papillomavirus and frequently present with primary sites in the tonsil or back of the tongue that stay very small and are only noticed after a neck mass begins to grow. HPV related head and neck cancers are not associated with a smoking or drinking history.

Other causes of lymph node swelling can be cancers that start in the lymphatic system, known as lymphomas .These can be divided into Hodgkin lymphoma, which often is curable, or non-Hodgkin lymphoma, which has varying prognoses depending on the type.

Thyroid nodules can be solid or filled with fluid. The thyroid gland is located at the base of the throat near the windpipe. Thyroid nodules can be large enough to form a visible lump or cause difficulty breathing or swallowing.

Few thyroid nodules are cancerous, but you should see your primary care physician or ENT for this condition. Risk factors for thyroid cancer include being assigned female gender at birth, between the ages of 25 and 65 years old and radiation exposure.