<s>[INST] I have had knots to form over the last year in the krook of my elbows. They seem to be muscle related and become sore and achey after doing a repetitive or strenguous exercise with my arms. I wonder if they are related to donating plasma on and off for a few years. Another one has popped up the last few weeks and I haven t given plasma in this arm for almost a year. [/INST] Hi, DEar, thanks for your query to Chat Doctor. I studied your query in depth.1-In My opinion the sore lumps which popped up last few was, most probably are due to the -post-donation thrombophebitis with fibrosis tissue in it-.2-Still you should check up for the Drums disease-which are painful lipomas, which could be other possibility for such lumps, without any relation to the donation.3-Hope this would solve your query.4-Wellcome for any more questions on new or this subject also... Have A Good Day.!! </s>