If I suffer from one type of autoimmune disease, can it be likely that i'll be susceptible to others?
Autoimmune . There is increased risk of autoimmune disease if first degree relatives are afflicted. There is a mildly increased risk of developing a 2nd autoimmune disease if you already have one, but this is not very common.
Higher chance of it. A person with autoimmune disease has a higher chance of getting another autoimmune disorder, such as thyroiditis, type 1 diabetes, rheumatoid arthritis, lupus, grave's disease, vitiligo, etc... However, having an increased risk of getting a disorder doesn't mean the person will surely get it. He might be only a little unlucky and have just one disease.