Lymphoma is a type of cancer that affects the lymph nodes of your body. These are parts of a widespread system called the lymphatic system, which also includes organs like the splene. It has other functions, like allowing fluids to circulate through your body, and helping in the processing of fat. There are white cells inside the nodes of the lymphatic system, and when they mutate, they can become a tumor and cause cancer.
Other tissues in the lymphatic system can be affected by lymphoma as well. The typical symptom of lymphoma are swollen nodes that you can feel under your skin, especially under your armpits, on your neck or throat, or your groin area. However, there are other symptoms that are less evident but could be a hidden sign that you are developing a lymphoma. All these symptoms require a medical diagnosis because none of them si specific of this condition.
Altough the swelling of nodes that is characteristic of lymphoma is very rarely painful, if you have lymphoma you could feel pain somewhere else in your body. When your white cells become malignant, they start reproducing at a pace too high, and the increasing number of them can press your tissues from the inside, which is felt as severe pain. The pain will be felt wherever the cancer is growing.
For example, if your abdominal organs or the abdominal part of your lymphatic vessels are affected, you will feel stomach cramps. If the cancer is growing in your head, you will feel a headache. The pain will always appear to start at random, with no apparent explanation. In some cases, the consumption of alcohol can trigger the cramps, altough the reasons are yet unknown. The pain is severe as all malignant cancers, and requires medical attention and a diagnosis.