He was hiding the fact that he was an illegitimate child.

My grandfather is suffering from arthritis.

My younger brother had an appendectomy yesterday.

I went to the doctor because of sinusitis.

My father was diagnosed with uveitis.

He was hospitalized due to meningitis.

If you don't have regular dental check-ups, you may develop periodontitis.

He is receiving treatment for folliculitis.

She was diagnosed with salpingitis.

My father was diagnosed with ankylosing spondylitis.