Disclosing health condition to new employer?

I recently took on a new employee and didn't know they had any health conditions until I had a 1:1 with them on the first day when they made me aware of what the condition was and what accommodations have helped them in the past. I also received an email from HR a few days later telling me much the same about the new employee and asking if I needed help making any accommodations. So my advice is, tell your line manager on day 1, and also make sure that HR are aware (also on day 1). As with all things in life, be polite, firm, and accommodating and then expect the same from others. For example: "Hey, I wanted to let you know that I have Reddit Syndrome which means I need to attend a regular monthly check-up at the hospital. This normally takes a few hours. At my previous employer I made that time up by working extra hours on Mondays and Tuesdays. My previous employer also provided me with a trackball-mouse and standing desk." Good communication with your line manager also helps, don't assume they will remember everything you tell them. So even in a year's time, "I am going to the hospital next week and I'll make the time up on Monday and Tuesday as usual". And put that in your calendar