He is suffering from depression.

Every day, I tend seedlings in the garden.

My hobby is tending seedlings.

He described the scenery in detail.

His description was so detailed, it made me feel as if I was there.

He was in a sickbed for a long time.

I decided to take a sick leave.

His grandfather is suffering from Alzheimer's disease.

He is an expert in pathology.

She was diagnosed with Addison's disease.