why does my friends back hurt so bad?

I have suffered back pain for a long time however I have scoliosis ( a curve in the spine) You for sure do not have scoliosis as the pain does not come on strong and fast. Plus it is really rare in males. If he has done anything physical in the last few days then it is probably just really mad muscle spasms, and if you don't want to go to the doctor to get muscle relaxers just keep doing what your doing. Ice and heat (heat usually works better). I know you didn't want me to say this but if it continues to get worse or doesn't get better in a few days and his side starts to hurt you should go to the doctor. The first sign of a kidney infection is back pain, i've had one and it is not fun! Without antibiotics it will not get better and could be fatal.

In the meantime, drink lots of water, and keep heat or ice on your back, also try hot baths! I hope it gets better soon so you don't have to go see a doctor!

If his family members' backs are hurting as well, perhaps it's something genetic like scoliosis. However, it's strange for that to suddenly flare up in the middle of his life and cause him pain. If it hurts when he breathes, it sounds like something is bruised or broken. When you breathe, your lungs inflate. When your lungs inflate, they press against your ribs and/or backbone and cause pain to the area. Like I said, that usually only happens when something is bruised or broken.

Alternate using ice then heat, and try to locate a FREE clinic in your area. There is usually one or more in every town. It may be located around or near a homeless shelter.