Harrison's Manual of Medicine
- Waldenström's macroglobulinemia
- wasp sting
- water displacement
- water requirements
- weaning, from mechanical ventilation
- Weil's syndrome
- Wernicke's encephalopathy
- Wernicke-Korsakoff's syndrome
- WFNS (World Federation of Neurosurgical Societies) Scale, for subarachnoid hemorrhage
- wheal
- whiplash injury
- whole blood transfusion
- whooping cough: see pertussis
- widow spider bite
- Wilson's disease
- winking owl sign
- Winter's formula
- Winterbottom's sign
- withdrawal of care
- Wolbachia
- Wood's light examination
- World Federation of Neurosurgical Societies (WFNS) Scale, for subarachnoid hemorrhage
- wrist, muscles and innervation of
- Wuchereria bancrofti infections: see filariasis