What do your lymph nodes do

The body contains hundreds of lymph nodes. They form clusters around the body and are particularly prominent in areas such as the neck, armpit and groin and behind the ears.

During this process, they catch bacteria and viruses that could harm the rest of the body. Due to their function, they come into contact with toxins, which can cause them to swell. Although swollen lymph nodes are common, they may occasionally indicate lymph node cancer, or lymphoma. In certain areas of the body, such as the neck, armpit, and groin, lymph nodes sit close to the skin. This means a person may feel them swell when an infection develops.

Lymph nodes are also present in the stomach and between the lungs. However, there are no lymph nodes in the brain or spinal cord. Lymph nodes form clusters throughout the body. Their main function is to filter out potentially harmful substances. All tissues and cells in the body excrete lymphatic fluid, or lymph, in order to eliminate waste products.

The lymph then travels through vessels in the lymphatic system and passes through lymph nodes for filtering. Lymph nodes contain lymphocytes. These are a type of white blood cells that help destroy pathogens, such as bacteria, viruses, and fungi. When lymph nodes detect a pathogen in the lymph, they produce more lymphocytes, which causes them to swell.

Upon encountering bacteria or damaged cells, lymph nodes destroy them and turn them into a waste product. When the lymph reenters the bloodstream, waste products travel to the kidneys and liver. The body then excretes waste products in the urine and feces.

Learn more about how the lymphatic system works here. Swollen lymph nodes do not always indicate cancer. Below, we list some of many conditions that can cause lymph node swelling. Lymphadenitis occurs when bacteria, viruses, or fungi in the lymph infect lymph nodes. When this happens, lymph nodes swell and are painful to the touch. If multiple clusters of nodes become infected, a person may feel pain and swelling in both their neck and groin.

The most common type of lymphadenitis is localized lymphadenitis. This means the condition only affects a few nodes. If the infection occurs in several node clusters, a doctor will likely diagnose generalized lymphadenitis. A doctor will help a person choose the most suitable treatment based on these factors. Learn more about swollen lymph nodes in the neck here.

Swollen lymph nodes in the neck may be due to a viral or bacterial throat infection, such as strep throat. Lymph nodes drain lymph fluid from nearby organs or areas of the body.

Lymph fluid is carried to the lymph nodes by lymphatic vessels. The lymph nodes filter out harmful substances and waste products. They also contain immune cells called lymphocytes that destroy cancer cells and bacteria. If you have an infection or cancer , a lymph node may become swollen. If you are concerned about your lymph nodes, speak to your doctor. Sometimes cancer can start in the lymph nodes such as in lymphoma , but some others types of cancer can also spread from one part of the body to another through lymph nodes.

If a person has cancer, doctors examine lymph nodes carefully to see whether or not they are affected by cancer. They can do this by:. This is done to see if the cancer has spread or not. This helps doctors work out the best treatment for the cancer. Having swollen lymph nodes is only very rarely a sign of cancer. Lymph nodes may be swollen due to infection or inflammation.

Swollen lymph nodes may be in the neck, under the arm or anywhere else there are lymph nodes. They can swell up to several centimetres and may stay swollen for weeks after the infection has cleared up. Learn more here about the development and quality assurance of healthdirect content. The lymphatic system comprises a network of tiny vessels that carry lymph, the lymph nodes and the organs of the lymphatic system.

Read more on myDr website. The lymphatic system The lymphatic system is made up of a vast network of vessels, similar to blood vessels that branch out into all the tissues of the body.

Read more on Leukaemia Foundation website. B-cell lymphomas are caused by an excess of B-cell lymphocytes, a type of white blood cell. Read more on Australasian College of Dermatologists website. Read how to recognise and treat swollen lymph nodes.

Read more on raisingchildren. Kaposi sarcoma is a disease in which malignant tumours cancer can form in the skin, mucous membranes, lymph nodes, and other organs. Read more on Rare Cancers Australia website. Metastatic squamous neck cancer with occult primary is a disease in which squamous cell cancer spreads to lymph nodes in the neck and it is not known where the cancer first formed in the body.

Swollen lymph nodes Open pop-up dialog box Close. Swollen lymph nodes One of the most common places to find swollen lymph nodes is in the neck. Request an Appointment at Mayo Clinic. Share on: Facebook Twitter. Show references Fletcher RH. Evaluation of peripheral lymphadenopathy in adults. Accessed Sept. Jameson JL, et al. Enlargement of lymph nodes and spleen. In: Harrison's Principles of Internal Medicine. The McGraw-Hill Companies; Merck Manual Professional Version.

Papadakis MA, et al. Lymphangitis and lymphadenitis. McGraw-Hill Education; American Cancer Society. Lymph nodes and cancer. Related Mesentery Parts of the immune system Swollen lymph nodes.

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