Cholesterol (not cholesteral) is a fat-like substance.

We breathe using our diaphragm (not diaphram).

Food poisoning can cause diarrhea (not diarrea).

The eyedrops will dilate (not dialate) your eyes.

You should be immunized against diphtheria (not diptheria).

You visit the ophthalmologist (not opthmologist).

The prostate (not prostrate) is a gland.