I have swollen lymph node since 4 months it's the same size neither increasing nor decreasing.. I sometimes get pain in my neck where there is swollen lymph node.. I'm otherwise healthy..I don't have any other symptoms apart from sometimes I see black hair like strand in my phlegm sometimes, sometimes greenish-greyish phlegm and sometimes I feel pressure in throat and shoulder/neck blade when I take deep breath..these symptoms I started seeing recently since 1 month also I was Covid affected in April..then it all started.. I have neck and back pain almost daily which I assume it is bcoz I'm working professional.. what I can do for this.. I do not understand what is the cause of swollen lymph node. Kindly hep with the answer.