Symptoms such as weakness, feeling tired, shaking, sweating, headache, hunger, nervousness and irritability are signs that a person's blood sugar is getting dangerously low.
A person showing any of these symptoms should check their blood sugar. If the level is low (70 mg/dl), a sugar-containing food should be eaten right away.
Update Date 8/5/2014
Updated by: Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.