These are symptoms typically associated with Lymphoma:
painless swollen lymph nodes, in the neck, chest, armpit, groin or spleen.
Sweating and/or fever, especially at night.
Abnormal tiredness.
Weight loss.
Loss of appetite.
Persistent itching.
Persistent cough.
Persistent breathlessness (especially if the chest is affected).
These symptoms are vague and can be attributed to other causes. There is no effective blood test for lymphoma. MOST swollen lymph nodes are NOT lymphoma. However the only way to definatively diagnose lymphoma is to biopsy the affected lymph node.
So, if I had recurring swollen nodes or nodes that stayed swollen for a long time (months), I would request a biopsy.