Their view is based on evidence that, during a respiratory infection such as a cold or bronchitis, the body releases large amounts of a water-conserving hormone (known as antidiruretic hormone). Thus giving extra fluids while antidiruretic hormone secretion is high may theoretically lead to salt loss and fluid overload.
They searched the scientific literature, but were unable to find any trials providing definite evidence that giving increased fluids to patients with respiratory infections may cause harm.
"Until we have this evidence, we should be cautious about universally recommending increased fluids to patients, especially those with infections of the lower respiratory tract," they conclude.
###