Frequent urination is one of the very early signs of diabetes. It occurs due to too much glucose in the blood. If insulin is nonexistent or ineffective, the kidneys are unable to filter glucose back to the blood. They then try to draw extra water out of the blood to dilute the glucose. This keeps the bladder full
If you feel abnormally thirsty, especially if it seems to go hand in hand with frequent urination, get your blood sugar levels checked. If your body is pulling extra water out of your blood and you're running to the bathroom more, you will become dehydrated and feel the need to drink more to replace the water that you are losing
Those with high blood sugar levels often feel hungry because of loss of energy and extreme tirednes
High blood sugar changes the shape and flexibility of the lens of the eye distorting the ability to focus and causes blurred vision.
In Type 1 diabetes, the pancreas stop making insulin, possibly due to a viral attack on pancreas cells or because an autoimmune response makes the body attack the insulin producing cells. The body looks for an energy source because the cells stop getting glucose. It starts to break down muscle tissue and fat for energy. This results in weight loss. 
If you often feel nauseate and vomit frequently without a known cause, get your blood sugar levels tested
Due to lack of insulin, the body cells become energy starved and you feel tired
If you notice that your wounds are not heeling in normal span of time, get your sugar levels tested as poor circulation can limit the amount of oxygen and healing nutrients that reach a wound
Diabetes can affect every part of the body, including the skin. Skin problems are sometimes the first sign that a person has diabetes. These skin troubles may include bacterial infections, fungal infections, and itching
If your observe that you have been experiencing extreme mood swings without any reason, it's advisable that you get your blood sugar levels checked
