Widespread firm small less than cm lymph nodes 3 months, can feel multiple neck, supraclavicular, both axillas, ct none elsewhere, blood work normal, virology negative, 5kg weight loss, stable now, no infections except mild covid jan, cause??

Generally speaking lymph nodes less than a cm in size tend not to be malignant. Also the CT results are reassuring. My guess is that these are burnt out lymph nodes from a prior viral infection. I would continue a follow-up examination in 3 months to assure no changes. I see no need for a lymph node biopsy at this time.

You can watch and wait. You may feel the nodes every couple of weeks, if any of the lymph glands doubles in size, becomes painful, ulcerates, or other nodes become enlarged, or you develop fever, or lose weight, you should see a doctor. Wish you good health!