An insidious disease is any disease that comes on slowly and does not have obvious symptoms at first. The person is not aware of it developing.
Taber's Medical Dictionary Online website. Insidious.
Last reviewed on: 5/13/2019
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.