Dictionary

RIRS Retrograde intrarenal surgery.

risk factor Something that increases a person’s chances of developing a disease. For example, cigarette smoking is a risk factor for lung cancer, and obesity is a risk factor for heart disease.

ritonavir A medication (brand name: Norvir) in the protease inhibitor family that is used to treat HIV infection (AIDS). See also protease inhibitor.

Ritter disease See staphylococcal scalded skin syndrome.

river blindness A disease caused by a parasitic worm (Onchocerca volvulus) that is transmitted by biting blackflies that breed in fast-flowing rivers. The adult worms can live for up to 15 years in nodules beneath the skin and in the muscles of infected persons, where they produce millions of worm embryos (microfilariae) that invade the…

RLL Right lower lobe, the lower-right lobe of the lung.

RLQ Right lower quadrant, the lower-right quarter of the abdomen.

RML Right middle lobe, the middle-right lobe of the lung.

RMSF Rocky Mountain spotted fever.

RN Registered nurse. See nurse, registered.

RNA Ribonucleic acid.

RNA, messenger See messenger RNA.