Grading refers to how quickly the lymphoma may grow and develop. Staging is a term which describes where it is in the body, how many lymph glands are affected and whether it has spread to other lymph glands or other organs.

Most non-Hodgkin lymphomas fall into one of two main categories:

Low-grade (or indolent) These grow very slowly and may need little or no treatment for months or possibly years. When they do need treatment they are likely to shrink down, or even disappear completely. Some types of low-grade NHL can be cured with treatment, but others are likely to come back again at some time in the future. Follicular lymphoma is an example of a low-grade NHL.

High-grade (or aggressive) These types grow more quickly. They usually cause symptoms and will need immediate treatment. However, they are more likely to be completely cured than low-grade lymphomas. The usual treatment is chemotherapy. Diffuse large B-cell, and Burkitt lymphoma are types of high-grade lymphoma.

A commonly used staging system is described below:

Stage 1 One group of lymph nodes is affected.

Stage 2 Two or more groups of nodes are affected, but the lymphoma is only on one side of the diaphragm. The diaphragm is the sheet of muscle under the lungs that helps us to breathe. The part of the body above the diaphragm is the upper half, and below the diaphragm is the lower half of the body.

Stage 3 The lymphoma is on both sides of the diaphragm.

Stage 4 The lymphoma has spread beyond the lymph nodes, for example to other organs such as the bone marrow, liver or lungs.

As well as giving each stage a number, doctors also use a letter code – either A or B – to show whether or not you have specific symptoms. Your doctor will ask you whether you have lost weight or have fevers or night sweats. If you do not have any of these symptoms, your lymphoma will be classified as A. If you have these symptoms, it is B.

Occasionally, lymphomas can occur at unusual sites outside the lymph nodes, for example in the stomach. This is called extranodal lymphoma and the stage will include the letter E (for extranodal).

Once your doctor knows the type of lymphoma and the stage and grade, they can plan the most effective treatment for you.