Causes of a Lump on the Back of the Neck
Medically reviewed by Rochelle Collins, DO
A lump on the back of the neck, like most lumps on your body, can be caused by a wide range of issues. While the lump may be a symptom of a serious health problem like cancer, most lumps on the back of the neck are harmless.
It's fairly easy to find a lump on the back of the neck during daily bathing and dressing, even if you can't see it. While many harmless lumps improve on their own, treatments that align with the cause of the lump can reduce symptoms and promote healing. This can be key to avoiding complications when the lump is serious.
This article describes the symptoms and likely causes of a lump behind the neck. It also covers risk factors and when to seek tests or treatment for your symptoms.
Symptoms of a Lump on the Back of the Neck
Symptoms of a lump on the back of the neck can vary by person, the exact location of the lump, and its underlying cause. Other physical changes can also accompany the appearance of a lump in the back of the neck. This is often the case when the lump is linked with more serious causes, like an infection or cancer.
With causes ranging from harmless to serious, you may have any of the following symptoms with a lump in the back of the neck:
Being warm to the touch
Pus in the lump
Leakage of fluid, blood, or pus from the lump
The feeling of a hard and immovable lump (usually malignant, meaning cancerous)
The feeling of a soft and movable lump (usually benign, meaning noncancerous)
Learn More:When to Worry vs. Not Worry About Lumps Under Your Skin
Causes of a Lump on the Back of the Neck
There are many causes of a lump in the back of the neck. Some of the most common reasons include the following:
Enlarged cervical lymph node: Cervical lymph nodes are located in the back and sides of your neck. These bean-shaped organs that are part of your body's immune system filter foreign substances and produce cells that fight infections. Lymph nodes can become swollen due to an infection or other inflammatory disease. When these problems occur, the lymph nodes produce more white blood cells to fight the foreign substance, which causes the affected area to swell.
Benign lumps, such as:
Nodular acne: Nodular acne is the most severe type of inflammatory acne. It is characterized by intense redness, inflammation, deep nodules, and cysts.
Skin boil: A skin boil, also known as a furuncle, occurs when a bacterial infection affects a hair follicle and the surrounding tissue. This swollen follicle usually is sore or painful to the touch. It is often filled with pus and has a pus-filled white or yellow head.
Epidermoid cyst: An epidermoid cyst usually develops as a noncancerous, slow-growing bump under the skin. It may have an enlarged pore in the center. It can occur when the skin cells shed from the outermost layer move under the skin rather than shedding. It can also occur when a hair follicle becomes clogged.
Lipoma: A lipoma usually occurs as a painless growth under your skin. It comprises adipose (fat) tissue surrounded by a thin capsule, usually not attached to any nearby muscle. It is usually soft, rubbery, and movable with gentle pushing.
Muscle knot: A muscle knot is a hard, sensitive knot of muscles that can cause pain when touched. It can occur due to muscle injury, overuse, stress, or tilting your head forward too long.
Learn More:Causes of Lumps on the Neck
What Medications Can Cause a Lump on the Back of the Neck?
A lump on the back of your neck is not a known side effect of a specific medication. However, it can develop as an allergic reaction to an over-the-counter (OTC) or prescribed medication. It can also develop as a reaction to the following:
Allergies to laundry detergents used in clothes that touch the back of your neck
Allergies to hair and skin care products that come in contact with the back of your neck
How to Treat a Lump on the Back of the Neck
The treatment used for a lump in the back of the neck varies based on the cause and stage of the problem. It can also differ based on your age, symptoms, and other medical conditions.
A benign lump in the back of the neck may be treated with one of the following types of therapy to manage symptoms until the underlying problem resolves:
Antibiotics for swollen cervical lymph nodes
Warm compresses or a salve to draw the pus out of a boil, followed by cutting and draining it
Topical (on the skin) therapies, systemic (throughout the body) agents, photodynamic or laser therapy for nodular acne
Excision (simple surgery) to remove an epidermoid cyst or lipoma
Steroid injections, liposuction, or surgery to treat a lipoma
Hot and cold therapy, massage therapy, or dry needling to treat muscle knots
OTC medications like nonsteroidal anti-inflammatory drugs (NSAIDs) like Advil or Motrin (ibuprofen) and topical creams to relieve pain and inflammation
A malignant lump on the back of the neck may be treated with one or more of the following therapies to kill cancer cells and prevent its spread:
Neck surgery: Neck surgery is usually reserved for removing tumors and may be combined with other treatments to ensure that all cancer cells are killed.
Radiation therapy: Radiation therapy uses high-powered waves to shrink or destroy tumors by targeting the genetic material inside cancer cells and killing them.
Chemotherapy: Chemotherapy uses oral or injectable drugs to kill cancer cells.
Immunotherapy: Immunotherapy uses human-made antibodies to boost your immune system to identify better and destroy cancer cells.
Targeted drug therapy: Targeted drug therapy uses medications that interfere with the pathway that causes cancer cells to grow. These drugs vary based on the type of proteins targeted.
Complications and Risk Factors Associated With a Lump on the Back of the Neck
Most lumps on the back of the neck don't cause harm. While they may be annoying, these lumps are typically benign. However, they can sometimes indicate a more serious condition like an infection or cancer.
When a lump in the back of the neck persists and remains untreated, it can lead to the following complications:
Sepsis (spread of untreated bacterial infection through your bloodstream)
Growth and metastasis (spread) of cancer
Cancer occurs when the genes that regulate cell production and growth are damaged or mutated. You have a greater chance of developing a cancerous lump on the back of the neck if you have any of the risk factors:
Long-term tobacco use, including cigarettes, cigars, chewing tobacco, or snuff
Long-term alcohol use
Age 60 or older
Exposure or cancer-causing substances
Certain infectious agents, like human papillomavirus (HPV) and Epstein-Barr virus (EBV), that increase your risk of cancer
Use of menopausal hormone therapy
Immunosuppression (when your immune system does not function as it should)
Radiation exposure such as from medical scans
Exposure to ultraviolet (UV) radiation from the sun, tanning booths, and sunlamps
Are There Tests to Diagnose the Cause of a Lump on the Back of the Neck?
Tests to diagnose the cause of a lump in the back of the neck are important for identifying the cause and starting treatment of serious conditions as early as possible.
Your healthcare provider will likely perform a physical exam that includes questions about the severity and duration of your symptoms, your medical history, and your family history of diseases.
Based on the data gathered during your physical exam, your healthcare provider may use one or more of the following tests to diagnose a lump in the back of the neck:
Blood tests: A complete blood count (CBC) and other blood tests can measure the number of red blood cells, white blood cells, and platelets. Identifying certain enzymes or cancer markers can also indicate a lymphoma diagnosis.
X-ray: Uses electromagnetic radiation to examine internal tissues, bones, and organs
Computed tomography (CT) scan: Creates a three-dimensional (3D) image from multiple X-rays
Magnetic resonance imaging (MRI): Produces two-dimensional (2D) or 3D images of your organs, tissues, and skeleton using radio waves and a strong magnetic field
Positron-emission tomography (PET) scan: Highlights cancer cells in pictures by using an injection of a short-acting radioactive substance called a radiotracer
Biopsies: A biopsy removes a tissue sample for laboratory evaluation to diagnose a lump in the back of the neck. One of the following types of biopsies may be used:
Fine needle aspiration biopsy (FNA): A fine needle aspiration biopsy is often regarded as the best initial test to diagnose a lump in the neck. It involves extracting tissue by inserting a very thin needle into the lump.
Core needle biopsy: A core needle biopsy uses a larger needle to extract a piece of tissue from a lump in the neck.
Excisional biopsy: An excisional biopsy is when the entire lump is removed and evaluated.
Learn More:How Cancer is Diagnosed
When to See a Healthcare Provider
A lump on the back of the neck is usually not a symptom of a serious condition. A swollen lymph node is the most common cause of a lump on the back of the neck. However, it can be difficult to determine whether the problem needs treatment.
Contact your healthcare provider if you have any of the following symptoms with a lump on the back of the neck:
A lump that doesn't go away or improve after two to three weeks
A lump that increases in size
A lump that feels hard when you apply pressure
Irregularly shaped lump
Dysphagia (difficulty swallowing)
Unexplained weight loss
A lump on the back of the neck is a somewhat common problem. It can be caused by many issues, ranging from a clogged hair follicle to cancer. Most cases of a lump in the back of the neck do not present a cause for concern.
It is hard to know whether a lump on the back of the neck is a severe symptom. Getting a diagnosis as early as possible can help you find the reason for the lump.
A benign lump in the back of your neck may resolve on its own without treatment. Over-the-counter therapies like ointments and NSAIDs may be all you need to improve symptoms until the lump goes away. For more severe lumps, early treatment can help prevent the spread of disease or cancer, which can be a life-threatening issue.