The most common symptom of non-Hodgkin lymphoma is a painless swelling in a lymph node, usually in the neck, armpit or groin.
Lymph nodes, also known as lymph glands, are pea-sized lumps of tissue found throughout the body.
They contain white blood cells that help to fight against infection.
The swelling is caused by a certain type of white blood cell, known as lymphocytes, collecting in the lymph node.
But it's highly unlikely you have non-Hodgkin lymphoma if you have swollen lymph nodes, as these glands often swell as a response to infection.
Some people with non-Hodgkin lymphoma also have other, more general symptoms.
These can include:
Other symptoms depend on where in the body the enlarged lymph glands are (for example, swollen tonsils, a lump in the tummy, or skin rashes).
A few people with lymphoma have abnormal cells in their bone marrow when they're diagnosed.
This may lead to:
See a GP if you have any of the symptoms on this page, particularly if you have swollen glands that do not go away after 6 weeks.
While these symptoms are unlikely to be caused by non-Hodgkin lymphoma, it's best to get them checked out.