Non-Hodgkin's lymphoma is a cancer of the lymphatic system, which is a network of vessels and glands spread throughout your body.
The lymphatic system is part of your immune system. Clear fluid called lymph flows through the lymphatic vessels and contains infection-fighting white blood cells known as lymphocytes (see box on this page for more about lymphocytes).
In lymphoma, these lymphocytes start to multiply in an abnormal way and begin to collect in certain parts of the lymphatic system, such as the lymph nodes (glands). The affected lymphocytes lose their infection-fighting properties, making you more vulnerable to infection.
The most common symptom of non-Hodgkin's lymphoma is a painless swelling in a lymph node, usually in the neck, armpit or groin. Read more about the symptoms of non-Hodgkin's lymphoma.
How common is it?
About 80% of all lymphomas diagnosed are non-Hodgkin’s lymphoma. In the UK, more than 11,800 cases of non-Hodgkin's lymphoma are diagnosed each year.
Non-Hodgkin's lymphoma is associated with ageing, as the chances of developing the condition increase as you get older. The average age at diagnosis is around 65.
What causes it?
The cause of non-Hodgkin's lymphoma is unknown. Risk factors for developing it include having a medical condition that weakens your immune system, taking immunsuppressant medication, and being previously exposed to the Epstein-Barr virus (which causes glandular fever). Read more about the causes of non-Hodgkin's lymphoma.
Diagnosing non-Hodgkin's lymphoma
The only way to confirm a diagnosis of non-Hodgkin's lymphoma is by carrying out a biopsy (testing a sample of affected lymph node tissue). Read more about diagnosing non-Hodgkin's lymphoma.
Treatment and outlook
There are many subtypes of non-Hodgkin's lymphoma, but they can all be put into one of two broad categories:
- high-grade or aggressive non-Hodgkin's lymphoma is where the cancer develops quickly and aggressively
- low-grade or indolent non-Hodgkin's lymphoma is where the cancer develops slowly, and you may not experience any symptoms for many years
Survival rates for non-Hodgkin’s lymphoma vary greatly depending on the exact type, grade and stage of the lymphoma, and the person’s age.
Your recommended treatment plan will depend on your general health and age, because many of the treatments can cause serious side effects and complications, which can put a tremendous strain on the body. Treatments include chemotherapy, radiotherapy and biological therapy. Read more about the treatment of non-Hodgkin's lymphoma.
Despite their names, high-grade non-Hodgkin's lymphoma is easier to treat than low-grade non-Hodgkin's lymphoma. An average of 60% of people with high-grade non-Hodgkin's lymphoma are cured.
The difficulty with low-grade non-Hodgkin's lymphoma is that it does not cause symptoms until it is well advanced, by which time it is often too late to cure. However, it is possible to control symptoms for many years.
