Low blood sugar, also called hypoglycemia, is an issue faced most often by diabetics who have taken too much insulin, causing their blood sugar level to drop. This typically requires quick treatment with sugary drinks like orange juice or honey or candy. In severe cases, someone will require a shot of glucagon to bring the level back up. Some of the signs of low blood sugar are an irregular or fast heartbeat, fatigue, sweating, irritability, and tingling or numbness on the lips, tongue and cheeks. In severe cases, hypoglycemia can also cause confusion, loss of consciousness, seizures and blurred vision. If you are experiencing any of these symptoms, you should immediately consult a health care provider.