Swollen Lymph Glands

There are a number of causes of swollen lymph glands. The most common cause is infection. See your doctor if you have swollen lymph glands and you do not know why they have swollen, or if swollen lymph glands caused by an infection do not go down again within two weeks.

Cross-section diagram showing the lymph glands of the head and neck

Small lymph glands (sometimes called lymph nodes) occur throughout the body. Lymph glands that are near each other often form into groups or chains. Examples of where lymph glands group together are the sides of the neck, the armpits, and the groins. The diagram shows the main groups of lymph glands in the head and neck. However lymph glands occur in many other places in the body.

Lymph glands are joined together by a network of lymph channels. Lymph is a fluid that forms between the cells of the body. This watery fluid travels in the lymph channels, through various lymph glands and eventually drains into the bloodstream.

Lymph and lymph glands are major parts of the immune system. They contain white blood cells (lymphocytes) and antibodies that defend the body against infection.

Lymph glands are normally pea-sized. You can sometimes feel some under the skin. Lymph glands under the skin become more noticeable and easier to feel if they swell. They can swell to the size of marbles or even bigger.

You cannot see or feel lymph glands deeper in the chest or tummy (abdomen) if they swell.

Causes of swollen lymph glands include the following:

Infection - the common cause

The lymph glands near to an infection swell quickly and become tender as the immune system 'fights off' infecting germs (bacteria, viruses, etc). The lymph glands usually go back to their normal pea size when the infection is over. It can take a week or so for them gradually to go back to normal after the infection. Examples include the following:

  • Throat infections, tonsillitis, the common cold and tooth-related infections may cause lymph glands in the neck to swell.
  • Scalp skin conditions or even head lice may cause the lymph glands at the back of the head to swell.
  • Skin infections of the arm may cause lymph glands in the armpit to swell.
  • Infections of the leg or genitals, or nappy rash, may cause lymph glands in the groin to swell.
  • Viral infections such as flu (influenza), chickenpox or glandular fever (infectious mononucleosis) affect the whole body. You may then develop swollen lymph glands in various parts of the body such as the neck, armpit and groins. 

Cancers, lymphomas and leukaemias - the less common causes

Some cells from a cancer can break off and spread (metastasise) to nearby lymph glands via the lymph channels. These cancer cells then grow and multiply in the lymph glands and cause the glands to swell. For example:

As a rule, swollen lymph glands due to cancers, lymphomas and leukaemias develop more slowly than those due to infections. They also tend to be painless at first.

Other less common causes

Rarely, swollen lymph glands can be due to reactions to certain drugs, glycogen storage diseases, sarcoidosis and certain forms of arthritis. They may also be caused by less common infections such as HIV, Kawasaki disease, and tuberculosis (TB).

The treatment depends on the cause. Swollen lymph glands are like a marker of various conditions, all with different outlooks and treatments. So, for example, the common cause is due to a viral infection. In this case no specific treatment may be advised and the lymph glands will normally go back to normal after a week or so. However, swollen lymph glands caused by a cancer, lymphoma or leukaemia may need extensive treatment.

Swollen lymph glands due to viral infections are common. For example, lymph glands in the neck may swell up and down if you have frequent throat infections. This is of little concern. Swollen lymph glands are more of a concern if there is no apparent reason for them to swell. Tell your doctor if:

  • You find swollen lymph glands and you do not know why they have swollen. For example, you do not have an infection to cause them to swell.
  • Swollen lymph glands due to an infection do not go down again within two weeks.
Original Author:
Dr Tim Kenny
Current Version:
Peer Reviewer:
Prof Cathy Jackson
Last Checked:
02/08/2013
Document ID:
4519 (v40)
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