What is Hodgkin lymphoma?

Hodgkin lymphoma is a type of blood cancer that affects ​white blood cells​ called ​lymphocytes​ . It is also called a cancer of the lymphatic system.

The lymphatic system is a system of thin tubes and lymph nodes that run throughout the body. Lymph nodes are bean shaped glands. The thin tubes are called lymph vessels or lymphatic vessels. Lymphocytes circulate around the body in these vessels and through lymph nodes in a clear fluid called lymph. The lymphatic system is made up of several different organs, including the bone marrow, the spleen and the thymus gland.

The lymphatic system is an important part of our immune system. It plays a role in fighting bacteria and other infections. And it destroys old or abnormal cells, such as cancer cells. Lymph nodes commonly swell if we have an infection, such as a cold. But they usually go back to normal after a short time. Hodgkin lymphoma can cause your lymph nodes to swell, talk to your GP if you have swollen lymph nodes that keep getting bigger, or don’t go down.

The diagram below shows the lymph vessels, lymph nodes and the organs that make up the lymphatic system.

Read about the lymphatic system

Hodgkin lymphoma and non-Hodgkin lymphoma

There are 2 main types of lymphoma. They are called Hodgkin lymphoma and non-Hodgkin lymphoma.

Hodgkin lymphoma was named after the doctor who first recognised it. It used to be called Hodgkin's disease.

Hodgkin lymphomas have a particular appearance under a microscope. They contain cells called Reed Sternberg cells. Non-Hodgkin lymphomas look different under the microscope and do not contain Reed Sternberg cells. 

Reed Sternberg cells are a type of white blood cell called a B lymphocyte, that has become cancerous. B lymphocytes normally make ​antibodies​ to help fight infections.

Find out more about how antibodies work

Most lymphomas are non-Hodgkin lymphoma. It's important for doctors to be able to tell the difference between Hodgkin and non-Hodgkin lymphomas. They are different diseases and the treatment for them is not the same.

Read about non-Hodgkin lymphoma

This video explains what lymphoma is and how it starts. And the difference between Hodgkin lymphoma and non-Hodgkin lymphoma. The video lasts just over 3 minutes.

Where Hodgkin lymphoma can start

Because the lymphatic system runs through your whole body, Hodgkin lymphoma can start anywhere. It can also develop in more than one place in the body at the same time.

The most common place to notice it is in the lymph nodes in the neck. But it can start in any of the lymph nodes in the body, such as:

• the centre of the chest, called the ​mediastinum​

• armpit (axilla)

• tummy (abdomen)

• groin

Hodgkin lymphoma in organs

You can also get Hodgkin lymphoma in body organs, such as the lungs, bones or liver. This is known as extranodal disease.

Some people are diagnosed with Hodgkin lymphoma in their spleen. The spleen is a large organ to the left of your stomach. It is part of the lymphatic system and it helps to filter old or damaged blood cells and fights infection.

Hodgkin lymphoma can occur in either the tonsils or a gland in the chest called the thymus, but this is very rare. Lymphoma in these sites is usually non-Hodgkin lymphoma.

How does Hodgkin lymphoma affect the body?

When you have Hodgkin lymphoma, some of your white blood cells (B lymphocytes) become abnormal and multiply. You then have more lymphocytes than usual, but they can’t fight infections as well as they should.

The cells can then clump together usually within lymph nodes or other parts of the lymphatic system to form tumours. This can cause problems in the lymphatic system and the part of the body where they are growing. For example, if Hodgkin lymphoma is in the chest, the enlarged lymph nodes can compress the airway and cause shortness of breath, coughing and discomfort.

Other cancers that have spread to the lymph nodes

Remember that it's very common for other types of cancer to spread to lymph nodes. This is not lymphoma. Lymphoma is cancer that starts in the lymphatic system.

For example, if breast cancer spreads to the lymph nodes in the armpits it does not become lymphoma. The cancer cells that have spread to the lymph nodes are still breast cancer cells. So they are treated as breast cancer.

If your cancer has spread to the lymph nodes (and is not lymphoma), you should look at information about that type of cancer.

A-Z list of cancer types

Who gets it

Hodgkin lymphoma can happen at any age. In the UK it is more common between the ages of 20 and 24 and between 75 and 79 years old. In the UK, Hodgkin lymphoma is slightly more common in men than women.

Read about risks and causes of Hodgkin lymphoma

How common is Hodgkin lymphoma

Hodgkin lymphoma is not one of the common cancers in the UK. Around 2,200 people are diagnosed in the UK each year.