First let me say I am NOT a medical professional though I was in premed until life got in the way. I have what is called undifferentiated connective tissue disease. Basically it's an overlap of autoimmune diseases. A little of each but not enough of one to say definitely that you have Lupus or RA, etc. In my case Sjogrens is the main culprit with a little bit of Lupus thrown in to keep me honest I guess. Plus some other stuff. It's been a horrible ride since I was in my late 30s. I'm now 69 and just getting the answers. I've been told it's anxiety, been misdiagnosed and finally it's been blamed on the murder of my 3 year old grandson. So yes you can have multiples. Also a lot of symptoms are positive with a lot of diseases. That's what makes it so difficult for a Dr. to diagnose. They do their best but it can take awhile to get your answers. Best of luck to you and try not to let it get you down. Just be strong and confident when you talk to your docs. Don't let them tell you you're not feeling what you know you are feeling. Be strong. God's blessings