Basically morning sugar is another name for fasting sugar, which is a test undertaken to check and diagnose diabetes. As the name refers to, fasting sugar means not having any food or drink for at least 8 hours prior to testing. Ideally, morning hours are best suited for this test because you are waking up after some rest and hence the carbohydrate metabolism can be tested for your blood sugar levels.
In almost all cases, the morning sugar levels are much higher than your regular sugar levels. This happens because of hormonal changes that causes levels of glucose to rise. Individuals who don’t have diabetes tend to balance this with increased insulin production. But diabetic patients are unable to do the same.
Two contributing factors here include is the insulin resistance. This is a condition in which the muscles and the cells of the body are unable to use the insulin that our body makes in the correct way - thus failing to lower glucose levels. It also has an impact on how your liver processes and uses the stored sugar in the night. In normal human beings, small doses of sugar are released by the liver at night as your body sleeps. But for those suffering from type2 diabetes, the liver dumps a lot more sugar into the system. Hence it leads to a disastrous combination of hormones and liver resulting in higher blood glucose.
Though glucose levels are controlled during the day with exercise and diet, morning or fasting sugar is not. This is something that has to be treated via medication. Fasting sugar for a normal person (without diabetes) should be 70–99 mg/dl (3.9–5.5 mmol/L). For someone who has diabetes the ideal range should be 80–130 mg/dl (4.5–7.2 mmol/L). Anything beyond this would be considered risky.