Some things are better left unsaid. If you have a chronic health condition, and your situation is stable but still agonizing, after a while talking about it just doesn't do you much good.
There's actually scientific research that shows that talking about pain triggers the pain centers in the brain, therefore actually increasing it...
Of course being silent is not a good option either. You will want some people in your network that you can talk to about everything, you may want to be on a pain forum or have a support group where you can vent, but with the people in your daily life and more distanced acquaintances you might just want to take the whole "pain & problems" issue off the table and focus on other and more uplifting things.
Can you just by being there, listening, and giving a new perspective, help your friends or loved ones improve their situations or feeling better about something they are dealing with? If so you are lifting not only them, but also yourself.