If it's a gland up, there is a reason WHY that gland has come up. Often, infection or injury on the limb, or area nearest to the gland is the cause, but there are internal problems which could cause a gland to swell, which you couldn't see. If ALL his glands are up then that points to quite a serious infection or something similar which is affecting his whole system. Just one gland, and it is likely to be something wrong in some part of his body nearest to that gland.
But this might not be a swollen gland at all. It might be a hernia....or it might be something else. Only a vet can tell you.
Whatever, I do think there IS nothing you can do to fix it yourself. You need to take him to be checked by a vet. I wouldn't wait too long. If there is an infection it needs to be treated as soon as possible. If it is a hernia it could cause him great pain if not attended to.
Ginger gave you excellent advice. I am in total agreement with everything she said. Please post back after you see the vet and let us know what happens.