China 
Africa 
- Right subclavian artery
- Right to Know
- Right to die
- Right to health
- Right to left shunt
- Right to life
- Right upper quadrant
- Right ventricle
- Right ventricular hypertrophy
- Righting reflex
- Rigidity
- Rigler's triad
- Rigor mortis
- Rikenellaceae
- Rilmenidine
- Rilonacept
- Rilpivirine
- Riluzole
- Rima glottidis
- Rimantadine
- Rimexolone
- Rimonabant
- Rinderpest
- Ring enhancing lesion
- Ring structure
- Ring vaccination
- Ringer solution
- Ringer's lactate
- Ringworm
- Rinne test
- Riociguat
- Risankizumab
- Risdiplam
- Risedronic acid
- Risk benefit analysis
- Risk communication
- Risk factors
- Risk factors for breast cancer
- Risk management
- Risk management plan
- Risk matrix
- Risk mitigation
- Risk of infection
- Risk of mortality
- Risk stratification
- Risk-reducing surgery
- Risky sexual behavior
- Risorius
- Risperidone
- Risser sign
- Ristocetin
- Ristocetin induced platelet aggregation
- Ristocetin-induced platelet aggregation
- Ritalinic acid
- Ritanserin
- Ritodrine
- Ritonavir
- Rituximab
- Rivaroxaban
- Rivastigmine
- Rizatriptan
- RoGFP
- Road rash
- Road traffic
- Robenidine
- Roberts syndrome
- Robertsonian translocation
- Robinia pseudoacacia
- Robinow syndrome
- Robot ethics
- Robotic surgery
- Robotics
- Robustness
- Rockall score
- Rocker bottom foot
- Rocker-bottom feet
- Rocuronium
- Rod and Frame Test
- Rod cells
- Rod cone dystrophy
- RodA
- Rodenticide
- Rodenticides
- Roentgen
- Rofecoxib
- Roflumilast
- Rokitansky Aschoff sinuses
- Rolandic epilepsy
- Rolapitant
- Role model
- Role-playing
- Rolfing
- Rolipram
- Rolling circle replication
- Romano-Ward syndrome
- Romberg's test
- Romidepsin
- Romiplostim
- Romosozumab
- Rongeur
- Ronidazole
- Rooming-in
- Root canal
- Root canal treatment
- Root exudates
- Root nodules
- Root of the mesentery
- Root of the penis
- Root planing
- Root resection
- Root resorption
- Root sheath
- Rooting reflex
- Ropinirole
- Ropivacaine
- Rorschach test
- Rorγt
- Rosa canina
- Rosa × damascena
- Rosacea
- Rosai-Dorfman disease
- Rose oil
- Roselle
- Rosemary
- Rosenberg self-esteem scale
- Roseobacter
- Roseolovirus
- Rosiglitazone
- Rosin
- Rosmarinus
- Rosmarinus officinalis
- Ross River virus
- Ross procedure
- Ross' syndrome
- Rossmann fold
- Rostellum
- Rostral migratory stream
- Rostral ventrolateral medulla
- Rostral ventromedial medulla
- Rosuvastatin
- Rotary evaporator
- Rotation flap
- Rotational angiography
- Rotational correlation time
- Rotationplasty
- Rotator cuff
- Rotaviral gastroenteritis
- Rotavirus
- Rotavirus gastroenteritis
- Rotavirus vaccine