As someone who was once very ill indeed, and had to fill a lot of people in, and also as someone who has had "fussers" in my life who irritate me with the health questions they asked, let me offer some guidelines:
- DON'T ask "are you still" or "do you still" anything. I used to get really creeped out that something I mentioned in passing 2 weeks ago was being checked up on. If you know something is chronic, you can ask how it is (how is your pain today?) but don't use any phrasing involving "still"
- DON'T use the word "better" because it can mean "recovered" or "improved", leading to answers like "I'm better than I was but I'm not better yet". Be more specific in your questions.
- DO focus on the current moment by asking "how is your energy/pain/fatigue/mood?" instead of asking if it's better or worse than last time you talked, or at some acceptable or unbearable level.
- DO try offering observations rather than asking, but couch them precisely. "You look bright today, I hope that means you're feeling well too" or "It seems like [today, that trip, your doctor's appointment] took a lot out of you. Is there anything I can do to help?" Do not make observations about the progress of their disease or whether their meds are working. Restrict yourself to activity level, bright eyedness, alertness, tenseness or other observable things. The conclusions are the patients to draw.
- DO accept whatever the person tells you even if it seems patently untrue. If they say they are not tired and want to do something, don't try to stop them. If they say their pain is keeping them from doing something, don't try to chivvy them into doing it anyway. It is ok to ask once if there's something you could do that would make it possible.
- DO say the sort of things you would say to someone who isn't sick: I like your hair like that, that's a nice sweater, here let me help you with that [heavy thing, door, large item], are you sure that's ok I wouldn't want to impose, it's lovely seeing you, wow you look so relaxed, and so on.
Try to avoid yes or no questions, and not to ask a ton of questions in a row so they feel interviewed. Most leading questions are yes questions. Do you remember that? Are you feeling well today? Is the pain the same as before? People will say yes almost automatically. Asking things that require sentences as an answer is more likely to get an accurate response, and to give you something to hang a conversation on if you're not a caregiver assessing someone medically, but just a visiting relative or friend.
Imagine, "how's your energy?" "oh, I've got tons of energy, I went shopping yesterday and stocked up." "Oh, that sounds like a treat, where did you go?" [Or what did you get]. Now you're chatting about how they spent their day yesterday. You might have got that from "are you still having fatigue issues?" but you probably wouldn't. Same with "how is your pain?" compared to "is your pain ok today?"
Finally, I encourage you to think about why you're asking. If you're a caregiver, you need to ask these things and you need honest answers, although you may also just spend time observing and get information that way. If you're a friend or relative, you don't. It would be strange to visit without even mentioning the illness, but please have something else to discuss. There were times I wanted to do half an hour or an hour on my specific situation, what my last CAT scan or MRI was like, or how something was working or not working - but I didn't need much prompting in those cases. A lot of the time I would rather talk about what you're doing at work or your plans for summer vacation. And some times I wanted to quickly gloss through whatever medical questions I was asked and get into other topics - not be asked carefully chosen questions that would reveal as much information as possible to the asker. Just be careful, I'm saying.