A blood sugar level of 54 is very dangerous, as anything below 70 milligrams per deciliter is considered low, according to Healthline. Low blood sugar levels can cause fainting, seizure or a coma. Extremely low blood sugar is a medical emergency, requiring immediate consumption of 15 grams of carbohydrates.
Some symptoms that blood sugar is dropping too low are rapid heartbeat, pale skin and unexplained fatigue, notes Healthline. Symptoms such as tingling skin, shaking, sweating and sudden mood changes are also caused by low blood sugar levels. Good sources of carbohydrates that are quickly absorbed by the body are saltine crackers, honey and sugar. Hard candy, regular soda and juice are also acceptable choices to raise blood sugar levels quickly.