U
- Ulcer, duodenal
- Ulcer, gastric
- Ulcer, peptic
- Ulcerative colitis
- Umbilical cord prolapse
- Umbilical hernia
- Underactive parathyroid
- Underactive pituitary gland
- Undescended testes
- Undulant fever
- Unemerged tooth
- Unexplained pulmonary hypertension
- Unstable angina
- Upper extremity paralysis
- Ureteral reflux - adult
- Ureteral reflux - child
- Urethral infection
- Urethral irritation
- Urethral syndrome
- Urethritis
- Urge incontinence, female
- Urge incontinence--male
- Urinary incontinence, female
- Urinary incontinence--male
- Urinary tract infection
- Urinary tract infections in childhood
- Urticaria
- Usher syndrome
- Uterine cancer
- Uterine fibroids
- Uterine prolapse
- UTI
- UTI in childhood
- Uveitis