Broken ribs are very painful.
Although trauma to the chest or a fall can result in a broken rib, there are other things that can cause a broken rib.
In a study published by Katrancioglu and team at the University of Turkey, the study showed all the patients in that study had a cough followed by chest pain. The common ribs that were broken were the 4th and 9th rib. However, some patients in the study had multiple broken ribs. There were some risk factors identified which the authors suggested may have contributed to the broken ribs.
The other possible causes or contributing factors were chronic lung diseases, asthma and osteoporosis. Most of the patients with broken ribs were taking long term steroid medication. Steroids can make bones brittle making them prone to be broken.
The study did not show how the pain of broken bones were treated. But I am assuming that the patients were given pain medicine and followed up in the clinic to ensure the broken ribs were healing well.
I had a broken bone while playing rugby in Japan. You can read about it here. In the post I also suggest simple steps that you can follow to avoid pain during sleep or moving.