I had Hashimoto's for the past 15 years initially with no symptoms. Until 4 years ago I was diagnosed with systemic sclerosis. The symptoms of fatigue, joint pain and swelling, and some dysautonomia, all started with the onset of SSc.

If someone is having multiple symptoms, more likely they have more than one autoimmune condition. Better check with a good rheumatologist for autoimmune and inflammatory conditions in addition to endocrinologist, who is only looking at thyroid issues.