You may get low blood sugar due eating too few carbohydrates or taking certain medications. Treatment may include easily digestible carbs, medication, or urgent medical care, depending on severity.
Hypoglycemia (low blood sugar) happens when your blood sugar (glucose) drops below the typical range. If your blood sugar drops too low, you may need immediate treatment.
This article will take a closer look at hypoglycemia, as well as the symptoms and treatment and how to prevent your blood sugar from dropping too low.
Hypoglycemia occurs when your blood sugar drops below 70 milligrams per deciliter (mg/dL). Blood sugar is also known as blood glucose. If your cells don’t get glucose, your body can’t perform its typical functions.
If you take insulin for diabetes, you may be more likely to develop hypoglycemia.
Even a short-term decrease in blood glucose can cause problems. In this situation, immediate treatment for low blood sugar levels can help prevent more serious symptoms such as loss of consciousness.
Symptoms of low blood sugar can occur suddenly. They may include:
- pale skin
- unexplained fatigue
- rapid heartbeat
- mood changes
- irritability or anxiety
- difficulty sleeping
- skin tingling
- blurry vision
- trouble thinking clearly or concentrating
- loss of consciousness, seizure, or coma
Some people may have low blood sugar without any symptoms. This is called hypoglycemia unawareness.
If you have this condition, your blood sugar can drop without you noticing it. Without immediate treatment, you may faint, experience a seizure, or even go into a coma.
If you have hypoglycemia unawareness, you may need to check your blood sugar levels more regularly. A doctor may recommend a continuous glucose monitor, a device that can alert you to changes in your blood sugar levels.
What to do if you have low blood sugar symptoms
If you have diabetes and are experiencing mild to moderate hypoglycemia symptoms, you need to immediately eat or drink 15 grams (g) of easily digestible carbohydrates.
Examples of easily digestible carbohydrates
- 1/2 cup of juice or regular (non-diet) soda
- 1 tablespoon of honey
- 4 or 5 saltines
- 3 or 4 pieces of hard candy or glucose tablets
- 1 tablespoon of sugar
Very low blood sugar is a medical emergency. If you or someone else with diabetes is experiencing severe symptoms, such as loss of consciousness, it’s important to administer a medication called glucagon and contact local emergency services immediately.
If you’re at risk for low blood sugar, a doctor can prescribe glucagon.
Never give an unconscious person anything by mouth, as it could cause choking. If you have diabetes, make sure your family and friends know not to do this if you lose consciousness.
Low blood sugar can occur for a number of reasons. It’s usually a side effect of diabetes treatment.
Possible causes in people with diabetes
If you have diabetes, your blood sugar levels may sometimes become too low as a result of your treatment. Hypoglycemia may also occur if you:
- take too much medication, including insulin or medications that increase insulin production
- plan to eat a big meal and take your medication accordingly but then do not eat enough
- skip meals or fast
- eat less than usual
- eat later than usual but take your medication at the usual time
- engage in unplanned, excessive physical activity without eating enough
- drink alcohol, which can affect how your body manages your blood sugar levels
- become sick and cannot keep food down
Blood sugar regulation
Blood sugar regulation aims to prevent spikes and drops by keeping your blood sugar levels stable.
If you have untreated diabetes or are unaware that you have diabetes, you may experience low or high blood sugar. You can help manage your blood sugar levels with dietary changes, regular physical activity, and medication if needed.
Hypoglycemia after meals
You may develop low blood sugar levels after eating due to the composition of your meals. Contributing factors can include:
- consumption of too few carbohydrates
- consumption of too few carbohydrates without a reduction in the amount of insulin you take
- consumption of more carbohydrates from liquids than usual, as your body absorbs them more quickly than solids
- the amounts of other nutrients, such as fat, protein, and fiber, you are consuming
Possible causes in people without diabetes
Even if you don’t have diabetes, you may experience low blood sugar, though it is less common.
Possible causes of low blood sugar in people who don’t have diabetes include:
If you suspect you have low blood sugar, it’s important to check your blood sugar right away. If you don’t have a blood glucose meter and you’re taking diabetes medications that increase insulin, talk with your doctor about getting a meter.
If you experience low blood sugar a few times per week, talk with a doctor right away to find out why. They may begin your visit by requesting your medical history, asking questions about your eating habits, and learning more about your symptoms.
If you don’t have diabetes but suspect you have hypoglycemia, talk with a doctor about your symptoms. A doctor will use three criteria, sometimes referred to as Whipple’s triad, to diagnose low blood sugar:
- Signs and symptoms of low blood sugar: A doctor may require you to fast (abstain from drinking and eating for an extended period) so they can observe signs and symptoms.
- Documentation of low blood sugar when your signs and symptoms occur: A doctor will order a blood test to analyze your blood sugar levels in a laboratory.
- Disappearance of the signs and symptoms of low blood sugar: A doctor will want to know whether the signs and symptoms go away when your blood sugar levels are raised.
The doctor may send you home with a blood glucose meter to track your blood sugar over time at home. They may ask that you check your blood sugar at certain times of the day, such as after waking up and after eating meals.
How to check your blood sugar at home
To perform a blood sugar test, you will need to prick your finger with a lancet (provided in a blood glucose test kit). You’ll put a small sample of blood from this onto a strip inserted into the blood glucose meter.
Before you check your blood sugar at home, it’s important to find out from a doctor what a healthy blood sugar range is for you. The doctor will determine this range based on factors such as:
- the type of diabetes you have
- how long you’ve had diabetes
- your age
- whether you have any other chronic health conditions
If you don’t have a blood glucose meter on hand and are experiencing symptoms of low blood sugar with diabetes, your symptoms may be enough to diagnose low blood sugar.
You can treat hypoglycemia by raising your blood sugar. It is important to treat low blood sugar as soon as possible.
The American Diabetes Association recommends consuming at least 15 g of carbohydrates to increase your blood sugar. Options include:
- hard candies
- non-diet soda or juice
- honey or table sugar
- jelly beans or gumdrops
- fresh or dried fruit
You can also take glucose tablets to rapidly raise your blood sugar if it’s low, but it’s important to determine how many grams of carbs are in each tablet before taking them.
Wait 15 minutes after eating or taking a glucose tablet and check your blood sugar again. If your blood sugar is not above 70 mg/dL, eat another 15 g of carbohydrates or take another dose of glucose tablets. Repeat this until your blood sugar level starts to rise.
Be sure not to overeat. This could lead to blood sugar levels that are too high.
If your blood sugar remains unresponsive, contact a doctor or emergency services right away. Symptoms of low blood sugar usually get worse if left untreated and can become life threatening.
If you are at risk for low blood sugar, a doctor may recommend a glucagon kit. This medication raises your blood sugar levels.
You may also want to talk with people you are in frequent contact with about how to care for you if your blood sugar drops too low. This includes:
- recognizing low blood sugar symptoms
- knowing how to use the glucagon kit
- calling 911 or your local emergency services if you lose consciousness
Wearing a medical identification bracelet can help emergency responders care for you properly if you need urgent medical attention.
You may need to make an appointment with a doctor if you have diabetes and experience low blood sugar levels often or if you have symptoms but don’t have diabetes.
Mildly low blood sugar levels are somewhat common for people with diabetes. However, severely low blood sugar levels can be life threatening. Complications may include:
- nervous system damage
- loss of consciousness
Avoid driving if you are experiencing low blood sugar, as it can increase your risk of having an accident.
There are several ways you can prevent low blood sugar.
Check your blood sugar often
Regularly checking your blood sugar level can help you keep it in your target range. If you’ve had low blood sugar episodes in the past, you may want to check your blood sugar levels before driving or operating machinery.
A doctor can advise you on how often to check your blood sugar.
Consider having a snack before you leave your home if you know it will be more than 5 hours until your next full meal or if your blood sugar levels are lower than 100 mg/dL.
It’s a good idea to keep carbohydrate-rich snacks on hand at all times in case your blood sugar dips while you’re out.
Fuel your body during exercise
Exercise uses up energy, so it can quickly cause your blood sugar to drop if you haven’t eaten enough beforehand. Check your blood sugar 1–2 hours before exercising to make sure it’s within your target range.
If it’s too low, eat a small meal or carbohydrate-rich snack.
If you plan to exercise for an hour or longer, consume additional carbohydrates during your workout. Exercise gels, sports drinks, granola bars, and even candy bars can provide your body with a quick burst of glucose during exercise.
Healthcare professionals can come up with the right program for you.
Your blood sugar may drop for up to 24 hours after moderate to intense exercise. Doctors recommend checking your blood sugar level immediately after exercise and then every 2–4 hours until you go to sleep. Avoid intense exercise immediately before bed.
Follow guidance around medications
If you follow a meal plan or take medications that increase your insulin level, it’s important to stick to the plan your doctor has prescribed to help prevent low blood sugar.
Not eating the right foods or taking the right medications at the correct times can cause your blood sugar to drop. Check in often with your doctor so they can adjust your treatment plan if and when necessary.
I just started a weight loss program, and I keep having a big drop in my blood sugar levels after breakfast. Any advice?
It sounds like you may be experiencing something called reactive hypoglycemia, or low blood sugar after eating a meal, which is most likely due to a change in diet.
To manage this problem, I recommend consistent and frequent meals and snacks every 3–4 hours that are a mix of high fiber carbohydrates, fat, and protein.
Eating high fiber carbohydrates is important because they provide the sugar the body needs, but they are also what causes the body to release insulin.
Make sure to add some protein or fat to all of your meals and snacks. Protein and fat can help slow the digestion of carbohydrates, which helps manage the release of insulin and allows for the slow and steady digestion of carbs.
Be sure to discuss any changes to your diet with your primary care physician.
— Peggy Pletcher, MS, RD, LD, CDCES
Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.
Hypoglycemia (low blood sugar) can happen when your blood sugar level drops below 70 mg/dL.
Hypoglycemia is most common in people with diabetes. But it may also occur in people who don’t have diabetes, typically due to medication or a medical condition.
If you’re experiencing mild or moderate symptoms, it’s important to eat or drink 15 g of easily digestible carbohydrates right away. If your blood sugar drops too low, it can become life threatening and need immediate treatment.