India, Oct. 29 -- Marathons are long-distance runs, and staying hydrated is high on a runner's checklist. Reaching for water at every checkpoint may seem like the sensible thing to do, but drinking more than your body needs can also pose grave health risks.ALSO READ: Why do you wake up with a dry mouth even after drinking enough water? ENT doctor shares why it happens and when it can be serious

Before you sign up for a marathon this season, make sure you are aware of the risks of overhydrating and how to stay hydrated safely.

Let's take a quick look at a health risk runners should know about: a condition called exercise-associated hyponatraemia (EAH).

Dr Judhajit Sengupta, consultant, critical care medicine, Narayana RN Tagore Hospital...