Blood sugar levels lower than 55mg/dL are considered dangerous
Anna Giorgi is a health and lifestyle writer who specializes in providing straightforward and accurate healthcare communications for consumers.
Dr. Danielle Weiss is the founder of the Center for Hormonal Health and Well-Being, a personalized, proactive, patient-centered medical practice with a unique focus on integrative endocrinology. She enjoys giving lectures and writing articles for both the lay public and medical audiences.
Type 2 diabetes is the most common cause of low blood sugar (hypoglycemia). Low blood sugar can also occur in people with type 1 diabetes and people who do not have diabetes.
The target level for normal blood sugar varies for each person and is based on factors like age, health issues, and the type of treatment you use. Blood sugar can also change during the day, based on the time of your last meal.
Normal blood sugar levels are between 80 and 130 milligrams per deciliter (mg/dL) before a meal and less than 180 mg/dL two hours after a meal.
For many people with type 2 diabetes, low blood sugar is defined as a blood sugar level below 70 mg/dL. At this level, you're likely to feel shaky or dizzy. You may also have a fast heartbeat, sweating, or headache. Knowing when low blood sugar occurs and how to fix it can prevent severe health effects and even save your life.
This article describes low blood sugar, what causes it, the symptoms, how it's diagnosed, and treatment for people with type 2 diabetes.
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Having low hypoglycemia levels affects everyone differently. It is common to have symptoms of low blood sugar when your level falls below 70 mg/dL. Your body reacts by releasing the stress hormone adrenaline (also known as epinephrine). The hormone promotes a “fight-or-flight” response that increases your blood circulation, heart rate, and breathing to prepare your body for danger.
Knowing how your body reacts to hypoglycemic effects can help you identify and treat the problem before it worsens.
Symptoms of low hypoglycemia levels happen quickly. Signs of low blood sugar in adults include the following reactions that can get worse as your levels continue to fall:
When blood sugar levels fall and stay low for several hours while you are asleep, symptoms of hypoglycemia can include:
It's important to note that if you have hypoglycemia frequently enough, you may no longer have symptoms. This is called hypoglycemia unawareness and it is a very dangerous condition.
Blood sugar levels that keep dropping without treatment can get very low. Severe hypoglycemia—defined as a blood sugar level below 55 mg/dL—can be treated with a glucagon injection or spray. The medication triggers a release of stored sugar from the liver, which raises blood sugar levels quickly.
However, severely low blood sugar is a serious condition. It can lead to seizures, coma, and even death if the levels remain low for an extended time.
Call 911 for immediate medical attention if:
Knowing how to take your blood sugar reading is important to managing your levels at home. The results can help you make informed decisions about your diet, exercise, and medication.
Your healthcare provider will give you instructions on the recommended timing and frequency of testing your blood sugar and your target ranges.
Here are a couple of ways you can check your blood sugar at home.
A blood glucose meter (glucometer) is a small, portable machine used to measure blood sugar at the time the blood is checked. Here are the steps to follow to check your blood sugar with a glucometer:
A continuous glucose monitor is a wearable device that continually tracks and provides blood sugar readings 24 hours a day. Most of these instruments provide a blood sugar reading every five minutes, though some take a reading as often as every 60 seconds.
There are two types of devices:
While a continuous glucose monitor can reduce the number of finger sticks you have to do daily, you may have to check your results against a blood glucose monitor twice a day to ensure the accuracy of your continuous glucose monitoring system.
Your healthcare provider can provide individualized target ranges for your blood sugar levels based on your age, medication, and other health factors. While there are no definitive borders between normal, too low, and too high blood sugar levels, these general guidelines apply for people with type 2 diabetes:
There are several factors that can cause low blood sugar in people with type 2 diabetes. For many people, hypoglycemia occurs even when they're following a recommended diabetes treatment plan. Here are some factors that can lead to low blood sugar.
Hypoglycemia occurs most often in people with type 2 diabetes who take insulin or oral medications that increase insulin production. Insulin lowers blood sugar levels when it is too high.
Taking too much insulin or other types of diabetes medications can allow your body to release more insulin than needed. Having excess insulin causes your cells to absorb too much sugar. As a result, there is not enough sugar in your blood.
More than 50% of severe hypoglycemic episodes occur during sleep. Called nocturnal hypoglycemia, it happens most often among people taking insulin. You increase your risk for hypoglycemia by skipping meals, exercising or drinking alcohol before bedtime, or not consuming enough carbohydrates before sleep.
Nightmares or calling out in your sleep can be symptoms of nocturnal hypoglycemia but many episodes go undetected—especially in people who sleep alone. Untreated nocturnal hypoglycemia can cause seizures, coma, and cardiovascular events that can affect a person's quality of life.
Your body makes glucose by breaking down the sugars and starches in the carbohydrates you eat. Glucose raises your blood sugar level when it enters your bloodstream. Without enough carbohydrates in your diet, your blood sugar levels can decline.
You increase your risk of hypoglycemia if you miss a meal or eat later than usual while taking insulin or oral medications for diabetes. If this happens while you reduce your carb intake, you can develop low blood sugar from the combination of increased insulin and decreased fuel for blood glucose.
Increasing exercise or another type of physical activity beyond normal can raise your risk of triggering a spike in insulin up to 24 hours or more after exercise, which can lower blood sugar. You can risk sudden hypoglycemia if you are already taking insulin or insulin-promoting medication. Checking your blood sugar level before exercise and monitoring insulin and carbohydrate intake are important for avoiding hypoglycemia.
Consuming alcohol while you are taking insulin or diabetes medications can cause hypoglycemia.
Your liver stabilizes glucose levels by storing carbs and releasing them into the bloodstream during fasting periods between meals and sleep. It also breaks down toxins like alcohol so the kidneys can flush them out.
For people with type 2 diabetes, the problem with drinking alcohol is that the liver cannot always do both of these jobs at the same time. Drinking alcohol may prevent your liver from maintaining your blood sugar in favor of metabolizing the alcohol.
While hypoglycemia occurs most often among people with diabetes, it can also happen to people who do not have diabetes. Nondiabetic hypoglycemia is rare. When it occurs, it usually involves one of two types of hypoglycemia:
Even with closely managing your blood sugar levels and following your diabetes treatment plan, it's possible to develop hypoglycemia. Knowing what blood sugar level is too low and how to manage hypoglycemia can help you identify the symptoms, recognize low blood sugar levels, and treat the problem before it becomes a serious health issue.
The American Diabetes Association (ADA) advises people with diabetes to use the 15-15 rule to raise blood glucose levels below 70 mg/dL to between 55-69 mg/dL. The diabetes rule of 15 is as follows:
Though you may want to eat more, overeating can increase your blood sugar levels too fast.
There are many ways to consume 15 grams of fast-acting carbohydrates. Some common items that meet this standard include:
A blood sugar level that falls below 55 mg/dL is considered extremely low blood sugar and is an emergency. If your blood sugar goes this low, you may become unconscious or otherwise unable to act on your own. That's why it's important to make sure that your friends, coworkers, and family members know how to help you if it happens.
If you have extremely low blood sugar, you will be unable to eat or drink. The only way to stop falling blood sugar levels is to consume emergency glucagon through an injection or nasal spray. If you qualify for it, your healthcare provider can give you a prescription for an emergency glucagon kit to have on hand for emergencies.
If you are treated with an emergency injection of glucagon, you should return to consciousness within five to 15 minutes. When you wake up, consume a small piece of fruit, candy, or juice and recheck your blood sugar levels after 15 minutes.
Managing hypoglycemia with type 2 diabetes will likely involve a team of healthcare providers who can help you with the different aspects of your care. If you are searching for providers who specialize in type 2 diabetes, try the following strategies:
Dealing with a chronic condition like hypoglycemia with type 2 diabetes can be a lifelong challenge. Financial constraints, difficulty making lifestyle changes, poor healthcare system communication, and perceived misconceptions about the disease can interfere with your ability to get the care you need to stick with a treatment program.
Consider reaching out to your primary care provider for help in the areas where you need it most. If their office cannot offer support, check with a local chapter of the American Diabetes Association or another diabetes support group. Search the website of the American Diabetes Association for resources where you can learn about the benefit of self-management and following a treatment plan.
Social media sites can also offer the benefit of input from others who have overcome the same barriers to self-management that you are dealing with. You can also try using smartphone apps to record your blood glucose data and remind you to take your medications.
You can access a wide range of resources for managing hypoglycemia with type 2 diabetes through national diabetes organizations. The services offered include educational resources, diabetes news, directories of healthcare providers, peer and professional support, and information that can help you navigate the physical, emotional, and practical aspects of living with type 2 diabetes.
Some of the leading national resources include:
Check with your healthcare provider about diabetes resources in your area that is sponsored by local chapters of national diabetes organizations, libraries, healthcare centers, health departments, or other organizations.
Low blood sugar (hypoglycemia) is when your blood sugar level falls below normal levels. Having type 2 diabetes and taking insulin or medications that promote its release can increase your risk for low blood sugar. People with type 1 diabetes as well as people who do not have diabetes can also have low blood sugar.
Your normal blood sugar level is based on factors like your age, other health conditions, and the type of treatment you use. It can also vary during the day as you eat and the food is changed into glucose. Normal blood sugar levels are between 80 and 130 milligrams per deciliter (mg/dL) before a meal and less than 180 mg/dL two hours after a meal.
For many people with type 2 diabetes, low blood sugar is defined as 70 mg/dL. The effect can make you feel shaky or dizzy. You may also have a fast heartbeat, sweating, or headache. Learning how to know when you have low blood sugar and what to do can help you correct it early and avoid complications.
It's normal to feel frustrated if you have to monitor your blood sugar levels despite your efforts to follow your diabetes treatment plan. However, it's important to understand that your efforts to identify and treat symptoms of hypoglycemia can affect your health and quality of life.
Untreated hypoglycemia that falls to extremely low levels carries the risk of seizures, a coma, or even death. Being prepared to act and fix low blood sugar levels quickly can help prevent these complications. Having the supplies that others will need to treat an extreme hypoglycemic event where you cannot care for yourself could protect even save your life.
Hypoglycemia and hyperglycemia can occur as short-term complications of type 2 diabetes at different times. Anyone with type 2 diabetes can have either of these conditions at one time. If you have type 2 diabetes, you should know what to do to correct your blood glucose level if it becomes either too low or too high.
People who are prone to hypoglycemia should eat every three or four hours. You can accomplish this by eating smaller meals and adding snacks throughout the day.
Low hypoglycemia levels can make you feel shaky, hungry, and sweaty. You may also feel dizzy and confused. Without treatment, you may have difficulty concentrating and speaking or seeing clearly. If low blood sugar levels become extreme, you may have a seizure or fall into a coma.
American Diabetes Association. The big picture: checking your blood glucose.
American Diabetes Association. Hypoglycemia (low blood glucose).
National Institute of Diabetes and Digestive and Kidney Diseases. Low blood glucose (hypoglycemia).
Centers for Disease Control and Prevention. How to treat low blood sugar (hypoglycemia).
Centers for Disease Control and Prevention. Monitoring your blood sugar.
National Institute of Diabetes and Digestive and Kidney Diseases. Continuous glucose monitoring.
Institute for Quality and Efficiency in Health Care (IQWiG). Hyperglycemia and hypoglycemia in type 2 diabetes.
Johns Hopkins Medicine. Hypoglycemia: nocturnal.
American Diabetes Association. Blood sugar and exercise.
American Diabetes Association. Alcohol & diabetes.
Endocrine Society. Hypoglycemia.
Endocrine Society. Severe hypoglycemia.
American Diabetes Association. Finding a new physician.
Anna Zernone Giorgi is a writer who specializes in health and lifestyle topics. Her experience includes over 25 years of writing on health and wellness-related subjects for consumers and medical professionals, in addition to holding positions in healthcare communications.
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