- Refractometer
- Refractory anemia
- Refractory anemia with excess blasts
- Refractory hypertension
- Refractory period
- Refreshable braille display
- Refrigerants
- Refsum disease
- Regeneration
- Regenerative Medicine Advanced Therapy
- Regenerative endodontics
- Regenerative medicine
- Regimen
- Regional cerebral blood flow
- Regional differentiation
- Registry of Toxic Effects of Chemical Substances
- Regorafenib
- Regression
- Regression discontinuity design
- Regret
- Regular insulin
- Regulator
- Regulator gene
- Regulator of G protein signaling
- Regulator protein
- Regulatory DNA sequences
- Regulatory T cells
- Regulatory enzymes
- Regulatory macrophages
- Regulatory sequences
- Regurgitant fraction
- Regurgitation
- Rehabilitation
- Rehabilitation counseling
- Rehabilitation engineering
- Rehabilitation in spinal cord injury
- Rehabilitation program
- Rehabilitation psychology
- Rehabilitation robotics
- Rehmannia
- Rehmannia glutinosa
- Rehydration
- Reiki
- Reinforcement
- Reinforcers
- Reinke crystals
- Reinke's edema
- Reinnervation
- Reissner's membrane
- Reiter's syndrome
- Rejuvenation
- Rel
- Rel homology domain
- Relamorelin
- Relapse
- Relapse prevention
- Relapsing fever
- Relapsing polychondritis
- Relapsing-remitting
- Relatedness
- Relational aggression
- Relationship education
- Relative Fat Mass
- Relative age effect
- Relative energy deficiency in sport
- Relative risk
- Relative risk reduction
- Relative standard deviation
- Relative survival
- Relaxation
- Relaxation training
- Relaxin
- Relaxin receptor
- Relaxometry
- Release factor
- Release modulator
- Releasing hormone
- Relebactam
- Reliability
- Relief
- Religiosity
- Religious beliefs
- Relugolix
- Remediation
- Remifentanil
- Reminiscence
- Reminiscence bump
- Reminiscence therapy
- Remission
- Remittent fever
- Remnant cholesterol
- Remogliflozin etabonate
- Remorse
- Remote control
- Remote ischemic conditioning
- Remote patient monitoring
- Remote surgery
- Remote therapy
- Remote work
- Remoxipride
- Remyelination
- Renal agenesis
- Renal artery
- Renal artery stenosis
- Renal biopsy
- Renal blood flow
- Renal calculi
- Renal calyces
- Renal cancer
- Renal capsule
- Renal cell carcinoma
- Renal circulation
- Renal clearance
- Renal colic
- Renal compensation
- Renal corpuscle
- Renal cortex
- Renal cyst
- Renal cysts and diabetes syndrome
- Renal dialysis
- Renal ectopia
- Renal excretion
- Renal failure
- Renal fascia
- Renal function
- Renal glomerulus
- Renal glucose reabsorption
- Renal glycosuria
- Renal hypoplasia
- Renal insufficiency
- Renal ischemia
- Renal medulla
- Renal medullary carcinoma
- Renal osteodystrophy
- Renal papillary necrosis
- Renal pelvis
- Renal pyramids
- Renal replacement therapy
- Renal sinus
- Renal sodium reabsorption
- Renal sympathetic denervation
- Renal threshold
- Renal transplant
- Renal tubular acidosis
- Renal tubule
- Renal tubules
- Renal ultrasonography
- Renal ultrasound
- Renal vein
- Renal vein thrombosis