I've read the other posts on armpit lumps here but am not sure if that applies to me in this case. I have been on a hectic travel schedule flying across time zones for over three months and last week I got back from the states to hong kong and barely a day later went on a 25 km trek for charity to raise funds. For three days after that I have been in painful agony as all my muscles creaked and ached, but a few painkillers later, the rest of me is ok except by armpits. Last 3 days I have been in agony since my armpits have been hurting and I noticed it was all lumpy and I freaked out coz I have no idea what that is. Does this have anything to do with stretching myself too much without rest jetlag the trek or coudl this be something more?