Teenagers taking GCSE’s or A-Levels over consecutive days could see performance significantly affected if they don’t drink enough fluids, according to hydration experts. It only takes 1% dehydration by weight to impact short-term memory by 13%. Water for Work and Home is warning parents and teachers that they must ensure students are properly hydrated as they face the onslaught of the exam season. Medical research looked at the dehydration affects on brain structure and function in healthy adolescents. The results of the study identified that hydration needs to be a major issue for adolescents, their parents and, crucially, their schools. In particular the study identified that significant negative effects of dehydration with structural changes in the brain equated to the same level of shrinkage expected in Alzheimers’ patients over a two and half month period, or 14 months of ageing in otherwise healthy individuals. The study investigated the impact of dehydration on brain function, using functional magnetic resonance imaging in 10 healthy adolescents. Each subject completed a series of exercises which resulted in dehydration. They were then tested for their cognitive performance.