Causes of non-Hodgkin lymphoma

These risk factors are:

Poor immunity For example, in people who are taking medicines after an organ transplant, in people who have HIV, and people who have rare medical conditions that reduce immunity. Despite the increased risk, NHL is still uncommon in people with these conditions.

Previous cancer treatment NHL is also slightly more common in people who have previously been treated for cancer before. Some chemotherapy drugs and radiotherapy treatments can increase a person’s risk of developing NHL many years later. The risk is very small, however, compared to the benefit of having the treatment in the first place.

Infection People who have previously been exposed to the Epstein Barr virus (which causes glandular fever) or the human T-cell lymphoma virus 1 (HTLV1) may have a slightly increased risk of developing lymphoma. Another type of lymphoma, which usually affects the stomach – MALT lymphoma – is known to be caused by a type of bacterial infection known as helicobacter pylori.

Coeliac disease People who have coeliac disease (an allergy to gluten that can
cause inflammation of the small bowel) have a slightly increased risk of developing
B-cell NHL or a rare type of T-cell lymphoma called enteropathy type T-cell
lymphoma (EATCL).

NHL isn’t infectious and can’t be passed on to other people. Other members of your family will not be more likely to develop NHL just because you have it, unless you have an identical twin. The identical twin of someone with NHL has a  slightly increased risk of developing it themselves.