reduce

Definition

verb
  1. to make something smaller or lower
    Example They used ice packs to try to reduce the patient’s temperature.
  2. to put something such as a dislocated or fractured bone, a displaced organ or part or a hernia back into its proper position so that it can heal
"…blood pressure control reduces the incidence of first stroke and aspirin appears to reduce the risk of stroke after transient ischaemic attacks by some 15 per cent"[British Journal of Hospital Medicine]
Medical-Glossary.com
www.medical-glossary.com/definition/reduce.html