High blood sugar occurs when the sugar (glucose) level in your blood rises above your target range. Eating too many calories, missing medicines (insulin or pills), or having an infection or illness, injury, surgery, or emotional stress can cause your blood sugar to rise.
Excessively high blood sugar (hyperglycaemia) can be a medical emergency--if left untreated, it can result in a diabetic coma, while chronic high blood sugar can damage the eyes, heart, nervous system, and kidneys.
Signs of high blood sugar include increased thirst and urination, headaches, fatigue, blurred vision, and a "fruity" smell to his breath. Watch video below for recipe