is a specific kind of: disease.

is a broader term that covers: NEC, necrotizing enterocolitis | gastroenteritis, intestinal flu, stomach flu | pelvic inflammatory disease, PID | empyema | pleurisy | pyelitis | pharyngitis, raw throat, sore throat | angina | arthritis | acne | urinary tract infection ... show more.

has as a part: inflammation, redness, rubor.