Most times stress worsens pain. Essentially stress causes a lot of different things to happen. First, it can affect your sleep. It can affect your mood. It can affect your perception of pain, so your tolerance for pain is lower, your threshold for feeling pain is a little bit higher, and it's also a negative spiral actually.
So as people feel more pain and they feel more stressed, they just feed off at each other. There are some exceptions however, and we see this sometimes in soldiers, for example, who are injured in combat. Sometimes the stress is so high they actually don't feel the pain at the moment because the body has this fight or flight response that there's no time to feel pain right now.
We've to just escape. We have to do what we have to do and get out of here. So sometimes people might not feel pain immediately in a very high stress situation, but generally speaking, the more stress that people are under the more likely they are to feel the toll of chronic pain.