Hypoglycemia (low blood sugar) occurs when your blood sugar (glucose) levels are less than or equal to 70 mg/dL and symptoms are present. It can be caused by a number of factors, depending on whether or not you also have diabetes.
In those with diabetes, hypoglycemia causes include not eating enough carbohydrates, exercise, alcohol consumption, taking medications incorrectly, and weight loss. In people without diabetes, hypoglycemia can be caused by medication, drinking too much alcohol, and certain illnesses and disorders. It’s also important to note that hypoglycemia usually doesn’t occur in people with type 2 diabetes who are only using dietary modifications.
People With Diabetes
If you have diabetes and take insulin or oral medications that stimulate insulin secretion, there are a number of factors that can cause hypoglycemia, including:
- Lack of carbohydrates: Carbs are the body’s main source of glucose, so if you don’t eat enough of them, your blood sugar may dip, especially if you reduce the number of carbs you’re taking in, but don’t adjust your medication accordingly.
- Delaying or skipping meals: If you take insulin or oral medications for diabetes, eating a meal later than you planned or skipping it altogether can result in hypoglycemia. Make sure you talk to your doctor about whether or not you should also skip your medication if you skip a meal.
- Exercise: While exercise is great for helping to reduce your blood sugar levels, lose weight, burn calories, and have more energy, if you have diabetes and you exercise without eating, exercise more than you normally do, or you delay your meal, you may become hypoglycemic. Make sure you have a snack along with you for before or after your workout, as well as a fast-acting source of carbohydrates like raisins, juice, or jellybeans, in case your blood sugar gets too low.
- Taking the wrong doses of medications or insulin: Too much insulin or oral diabetes medications can cause hypoglycemia.
- Not taking your insulin or medications regularly: People often see their doctor because their blood sugar is too high, yet in some cases, this is because they’re not taking their medications. If your doctor is under the impression that you are regularly taking your medications, yet your blood sugar is still high (because you haven’t been taking them), he or she may prescribe a higher dose to try to lower your blood sugar without knowing that you aren’t taking it. Then, if you do decide to take your medicine, you run the risk of hypoglycemia. To avoid this, be honest with your doctor about how well you’re doing with taking your medications and, if you’re not, why you aren’t. He or she needs to have an accurate picture of how well you’re complying to treat you accordingly and will work with you to figure out an alternative, if necessary.
- Drinking alcohol: If you’re taking insulin or an oral diabetes medication, drinking alcohol can cause hypoglycemia. This doesn’t mean that you can’t enjoy alcoholic beverages, but you need to consume them safely and be careful about checking your blood sugar levels while you do.
- Weight loss: Losing weight can make you more sensitive to insulin, resulting in needing less or no medication. However, because weight loss does make you more sensitive to insulin, it can cause hypoglycemia if you’re inadvertently taking too much insulin. Be sure to talk to your doctor about potentially reducing your dose if you’re losing weight.
- Tight blood sugar control: It’s important to realize that the tighter your glucose control, the higher your risk of hypoglycemia, especially early in treatment. If you’re on tight glucose control, you need to be given the proper tools, knowledge, and support to avoid severe hypoglycemic episodes while continuing to maintain glucose levels in the target range. Once in awhile, hypoglycemia is normal, but if it keeps happening, you should talk to your doctor about steps to stop your blood sugar from getting too low before it becomes an emergency situation.
- Kidney disease: One complication of diabetes is kidney disease, which can make your kidneys take longer to clear insulin from your system, potentially resulting in hypoglycemia.
People Without Diabetes
Hypoglycemia occurs far less often in people without diabetes. If you don’t have diabetes and you develop hypoglycemia, this indicates that something else is going on in your body. Potential causes include:
- Medication: Hypoglycemia can be caused by certain medications, especially in children or people with kidney failure. Medications that have been associated with causing hypoglycemia include taking someone else’s diabetes medication, the antimalarial drug Qualaquin (quinine), the antibiotic Zymaxid (gatifloxacin ), the antiarrhythmic drug cibenzoline, the antimicrobial drug Pentam (pentamidine), the nonsteroidal anti-inflammatory drug (NSAID) Indocin and Tivorbex (indomethacin), and glucagon.
- Drinking too much alcohol: If you don’t eat enough or don’t eat at all and you drink an excessive amount of alcohol, especially over the course of a few days, you may become hypoglycemic. The combination of too much alcohol and a lack of food can stop your liver from putting glucose into your blood, causing your blood sugar level to crash.
- Critical illnesses: Kidney disorders, severe hepatitis, long-term anorexia, malaria, and sepsis (a complication of getting an infection) are all illnesses that can potentially cause hypoglycemia.
- Hormonal deficiency: Adrenal disorders such as Addison’s disease and certain pituitary disorders can cause hypoglycemia, as can not having enough growth hormone in children.
- Producing too much insulin: Some people have an overproduction of insulin that can cause hypoglycemia. Certain tumors may cause this overproduction, as can enlarged beta cells in the pancreas.
- Insulin autoimmune syndrome: This is a rare condition in which your body makes antibodies that attack insulin, creating hypoglycemia. It can be part of another autoimmune disease or it can be caused by certain medications.
- Reactive hypoglycemia: This type of hypoglycemia occurs within a few hours after eating meals. Scientists aren’t sure exactly what causes it, but it can happen to people who have had stomach surgery because food passes into the intestine too quickly. It also occurs in other people too, perhaps due to an enzyme deficiency that makes it difficult for your body to break down food or having pre-diabetes, which can cause insulin to fluctuate.
There are some risk factors that may increase your potential for developing hypoglycemia.
Children with type 1 diabetes, the elderly, and people with hypoglycemia unawareness are at a higher risk of developing hypoglycemia.
Hypoglycemia unawareness can occur if you experience low blood sugars frequently, which can make your body desensitized to symptoms. The inability to feel symptoms such as sweating, shaking, increased heartbeat, anxiety, or hunger is dangerous because it can result in unconsciousness or even death.
If you experience hypoglycemia frequently, it’s important to talk to your doctor about it so you can get it under better control and avoid an emergency.
Taking Certain Medications
If you’re taking certain medications for type 2 diabetes, such as sulfonylureas, insulin, or a combination of insulin and non-insulin injectables, you have a higher risk of hypoglycemia. Some pill combinations and certain non-diabetes medications can also increase the risk for low blood sugar.
Talk to your doctor about when and how much of your medication to take so that you don’t make an error in dosing. Don’t take too much medication, and try to stick to a scheduled meal regimen to help keep your blood sugar regulated.
If you have diabetes and take insulin, smoking increases your risk of developing hypoglycemia. The nicotine in cigarettes, cigars, and pipes can cause low blood sugar, possibly because it changes your cells in such a way that they don’t clear insulin as well or as quickly.
When your baby is born prematurely, he or she is more at risk for developing hypoglycemia in the days following birth, especially during the first 48 hours. The reason for this is that when you’re pregnant, you pass sugar to your baby through the umbilical cord. Toward the end of your pregnancy, your baby will begin to store up some of the sugar you’re giving her in her liver to use after her birth. She’ll get the rest of the sugar she needs after birth from regular feedings of formula or breastmilk.
When your baby is born prematurely, the amount of sugar he has stored up is lower than that of a full-term baby since his liver isn’t fully developed. Since many preemies also have feeding difficulties at first, he may not be able to get the amount of glucose he needs once he burns through the small amount of sugar he has stored. Additional factors that can make the risk of hypoglycemia higher in preemies include:
- Breathing difficulties
- Difficulty maintaining body temperature
- Feedings have to be delayed at first
- The mother had diabetes while pregnant, creating too much insulin in your baby’s blood
- Any health condition that causes hypoglycemia
Though hypoglycemia can turn into a dangerous condition when it’s left untreated, it’s usually temporary in preemies and treated quickly and effectively. There are some disorders that may cause long-term low blood sugar, but these are rare.