Tell them that he cold hard truth about your illness and have them call you rheumatologist,

Use your FMLA... The only thing I feel that helped our nation in a major big way from the Clinton Afmjnistration. Your coworker will always give you a hard time, because it Sucks being short on staff. But they understand why you need days off.

Get information or brochures from your Dr. That explains what rheumatoid is? How this disease is not just arthritis? I dont tell people I have RA I tell them I have RD. Rheumatoid Disease no cure and my body is attacking itself doesnt know what is a good or bad cell? All vital organs can be effected along with severe fatigue. I tell people imagine having the worst flu ever, where you ache from head to toe. Fever and your joints feel like they are on fire. I get shocks like someone is flicking me with an elastic band. A pain in my right foot a few seconds later the same shocking pain in my left. I dont know from one second to the next how I am going to feel. I work at Costco and a part of my job is to get buggies from the parking lot. I can do 8 at a time and our weather is -28 without windchill? If my Rheumatoligist found out whst I do at work he eould kill me. I am thinking on getting a Dr.'s note saying I am physically not able to do that part of my job. Its very hard when people can look at us and say she doesnt look sick? But they really have no clue? I would love for one day that next person that says something to me about arthritis? I would love to say to them there is a difference with rheumatoid disease. I hope this helps? Have a good day.

I have some experience as I work in HR in Canada. They cannot ask you openly disclose any health details. I hate to say this, but people can be aware and try to push this anyway. I'm not a legal representative, so I don't know the exact limitations of your message. I do know that they cannot discriminate. My recommendation is to contact your HR (if you have one) and try to be discreet but ask about health limitations. There are some Duty to Accommodate for protected grounds. Even worth googling those details if you don't have HR.
I know lawyers are expensive, by may be worth it for even a half hour. I had a free 15 minutes through my employee assistance program. So, you could also consider that.
I'm sorry for your troubles. I'm in HR and I still suffer with discrimination. Keep track of all the details. That's what I do and you may be really glad you did. I hope this helps.

I hope the FMLA works for you. I lost my job because of RD.