If your loved one is stuck at home, or waiting and waiting for test results, well, that can be completely crazy-making. I think one of the nicest things you can do for someone in that spot is to ask a few, light questions and test the waters as to whether or not they want to talk about their situation. 

Set aside your curiosity in this conversation (very difficult for me) and LISTEN CAREFULLY to what your friend does and doesn't say. Let them lead this dance. Be respectful of what they want, and lean that direction. 

If they need to talk, set aside your to-do list and dinner plans, and focus solely on what they're saying, and what it means for them down the road. Let them talk through their feelings, without offering too many opinions or finger-wagging advice. You can do this, and the judgement-free space to think through things out loud will mean everything to them. 

If their vibe reads "COOL IT. I can't do this right now," then be prepared to shift accordingly. This is the moment when you might tell a story about something interesting or funny (but not scary or sad) that's happened in life or in the news in the last few days. Something to make them feel connected to the world outside their circumstances, offering them a little window out of their heads and back into life, you know? Actively listen for when they become tired. Then give them a hug and leave.