By Melissa Johnson Reviewed by Erin Palinski-Wade, RD, CDE Hypoglycemia can cause both short- and long-term complications. Know the signs so that you can treat the condition as soon as you're aware of it. Hypoglycemia, or low blood sugar, is common among people with diabetes and can occur even when you're carefully managing the condition. Hypoglycemia happens when the amount of blood glucose (sugar in the blood) drops to a level that's too low to sustain normal functioning; in most people, this is defined as a blood-sugar level below 70 mg/dl. A study review in the June 2015 issue of PLOS One found that among those with type 2 diabetes, this is a far too common occurrence: individuals had an average of 19 mild episodes of hypoglycemia a year, and nearly one severe episode per year on average. Low blood sugar was particularly common among those taking insulin. This decrease in blood-sugar levels can cause both short-term complications, like confusion and dizziness, as well as more serious, long-term complications. Left untreated, it can lead to a coma and even death. To prevent hypoglycemia and its dangerous side effects, it's crucial to monitor your glucose levels and treat low blood sugar as soon as you become aware of it. And pay attention to these telltale signs of dipping blood sugar levels to make sure yours stays under control: Ravenous hunger: If you've already eaten but still aren't satisfied, or if you suddenly, inexplicably feel as if you're starving, your body is signaling that it needs more glucose — preferably 15 grams from a carbohydrate-rich food source. Two tablespoons of raisins, 4 ounces of fruit juice, and hard candy (see package to determine how many to consume) are all good sources. Feelings of anxiety: When glucose levels fall too low, your body tells the adrenal glands to release the hormone ephinephrine (also called adrenaline), which signals the liver to make more sugar. The excess ephinephrine creates an "adrenaline rush," which can make you feel anxious. Restless nights. Nocturnal hypoglycemia, which is very common, can cause a number of sleep disturbances. Symptoms include night sweats, nightmares, episodes of waking suddenly and crying out, and feelings of unrest and confusion upon waking. A snack before bed can reduce the frequency and severity of sleep disturbances. Shakes and tremors. The central nervous system starts to malfunction when glucose levels are off balance. As a result, it releases catecholamines: chemicals that encourage glucose production and also produce these symptoms. Emotional instability: Mood swings and sudden emotional episodes not typical of your normal behavior are among the neurological symptoms of hypoglycemia, including irrational outbursts, random or hysterical crying, uncontrollable anger, and a strong desire to be left alone. Mild mood changes that may not be as severe, such as general irritability or becoming easily annoyed, can also be a signal that your blood sugar may be dropping. Sweating: This symptom is controlled by the autonomic nervous system (the part of the central nervous system that governs the skin, among other things) and is usually one of the first signs of hypoglycemia. The excessive perspiration comes on without warning, regardless of how warm or cold the external temperature may be. Dizziness and light-headedness: If you experience these common symptoms of hypoglycemia, heed them and treat the hypoglycemia quickly. Dropping blood sugar levels can also cause you to faint, so if you feel yourself start to swoon, sit or lie down immediately to avoid injuring yourself. Wandering thoughts. Because the brain is especially sensitive to a drop in glucose, you may experience a sense of confusion and an inability to concentrate on one thing at a time. Vision problems: If your vision suddenly becomes blurry or you see double, a drop in blood sugar may be to blame. Slurred speech. Your sugar-starved brain may not allow you to detect a change in how you sound, but others will notice a difference. To someone else, you may sound as though you've had a few too many cocktails — even though you haven't touched a drop.