My husband has given up smoking and drinking in order to train for a 10K run - He has always been underweight despite a normal diet and has always been very fit (prior to turning 40 - now 42). He has begun feeling unwell in the last couple of days - possibly over doing it, but, symptoms, such as waking up in the early hours as he is extremely thirsty, a little shaky at times and just generally unwell. He went for a 10K run today, followed by a sunday lunch a glass of water - he then checked his sugar on my Dad s machine and it read 20. Could he be diabetic or are his symptoms a result of overdoing it perhaps??