A stimulus is anything that can trigger a physical or behavioral change. The plural of stimulus is stimuli.
Stimuli can be external or internal.
An example of external stimuli is your body responding to a medicine.
An example of internal stimuli is your vital signs changing due to a change in the body.
- Temperature changes
Taber's Medical Dictionary Online website.
Last reviewed on: 2/7/2019
Reviewed by: Linda J. Vorvick, MD, Clinical Associate Professor, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.