What You Need to Know About Nausea From Low Blood Sugar

Your blood sugar level varies throughout the day, but when it dips too low (hypoglycemia), symptoms like nausea can occur. Low blood sugar happens in people with and without diabetes. It is defined as a blood glucose low enough that you need to take action to bring it back to your target range, typically when it's lower than 70 mg/dL. Regardless of your overall health, treating hypoglycemia immediately is important because it can lead to serious complications if left untreated. High blood sugar levels (hyperglycemia) can also cause nausea, so it’s important to measure your blood glucose to find out which is causing nausea. 

Stages of Low Blood Sugar

You will notice certain signs when your blood sugar begins to drop. These signs arise in stages, ranging from mild to moderate to severe. Each stage is characterized by a specific set of symptoms.

Nausea is one of the signs that occur in the mild stage, but it can also be present in later stages. Many organizations like the National Institute of Diabetes and Digestive and Kidney Diseases combine the mild and moderate stages into one.

Other signs of mild to moderate low blood sugar include:

• Blurred vision
• Confusion or cognitive changes
• Coordination issues
• Concentration issues
• Changed behavior or personality
• Dizziness or lightheadedness
• Extreme hunger
• Fast or irregular heartbeat
• Headache
• Irritability or mood swings
• Paleness or pallor
• Shaking
• Sleepiness
• Sweating
• Muscle weakness

Signs of severe low blood sugar include:

• Unable to eat or drink
• Seizures or convulsions (jerky movements)
• Unconsciousness (coma)

Symptoms of hypoglycemia during sleep include:

• Crying out or having nightmares
• Sweating enough to make your pajamas or sheets damp
• Feeling tired, irritable, or confused after waking up

Low Blood Sugar and Nausea

Whether people have diabetes or not, when they have mild low blood sugar, they may feel extremely hungry, often also nauseated. This symptom combination is the first sign of low blood sugar and is caused by the release of the stress hormone epinephrine, also known as adrenaline.

When your blood sugar drops, it triggers the fight-or-flight response, causing a surge of adrenaline. This flood of adrenaline functions as a helper, moving stored glucose into the bloodstream quickly. However, this surge isn’t without effects. Other symptoms like sweating, shakiness, and anxiousness can also be caused by this process.

That said, people with diabetes shouldn’t assume their nausea is always related to low blood sugar. The only way to know for certain is to measure your blood sugar. If your levels are within the normal range, other factors may be contributing to your nausea.

Causes of Nausea in People With Diabetes

People with diabetes can experience nausea for several different reasons. This is why it’s always important to check your blood sugar level before deciding on the appropriate course of action.

Medication

Glucophage (metformin) is used to lower blood sugar in people with type 2 diabetes, and nausea is both a potential side effect and a sign of Glucophage overdose. If you experience nausea while taking Glucophage or other brands of metformin, you should let your healthcare provider know immediately. 

Nausea is also listed as one of the most common side effects in injectable medications such as Victoza (liraglutide), Symlin (pramlintide), and Lantus (insulin glargine). If you feel nauseated while taking any of these injectables or if your nausea worsens with a dosage increase, it is important to tell your healthcare provider right away. They may decide to switch to a different medication for you.

High or Low Blood Sugar

Nausea is a symptom of both high and low blood sugar, so it is important to check your levels at home with your glucometer before deciding on your next steps. If you are experiencing blood glucose highs and lows regularly or more frequently than usual, tell your healthcare provider. They can help determine the cause and a plan of action to keep your blood sugar levels within the normal range. 

Gastroparesis

People with diabetes are at increased risk of having gastroparesis, also known as diabetic stomach, because diabetes can damage the nerve cells (including the vagus nerve) within the stomach wall. Damage to the vagus nerve decreases your stomach's and small intestine’s ability to move food through the digestive tract, which slows the emptying of your stomach and leads to a buildup of contents.

Medications for diabetes that delay gastric emptying, such as Symlin or other brands of pramlintide and GLP-1 agonists like Trulicity (dulaglutide), Victoza (liraglutide), and Bydureon (exenatide), can make symptoms of gastroparesis worse.

Symptoms of gastroparesis include:

• Feeling full soon after starting a meal
• Feeling full for a long time after eating a meal
• Nausea
• Vomiting
• Excessive bloating
• Excessive belching
• Upper abdominal pain
• Heartburn
• Poor appetite

Pancreatitis

People with diabetes also have a higher risk of developing pancreatitis. Pancreatitis refers to sudden and temporary (acute) or chronic inflammation of the pancreas. Your pancreas is responsible for releasing digestive enzymes and making insulin, both of which help regulate your body’s use of glucose.

Symptoms of pancreatitis include nausea and pain in your upper abdomen that may spread to your back. Pancreatitis requires immediate medical attention. 

Other symptoms of pancreatitis may include:

• Fever
• Rapid heartbeat
• Swollen, distended, and tender abdomen
• Vomiting
• Poor appetite

Diabetic Ketoacidosis

Diabetic ketoacidosis (DKA) is a life-threatening condition that occurs when there is a lack of insulin, which leads your body to burn fat for energy. It is characterized by very high blood sugar levels and ketones in your urine, which can be checked with an at-home testing kit.

If you have symptoms of DKA, which include feelings of severe nausea, contact your healthcare provider or seek emergency medical care right away.

Other symptoms of DKA include:

• Fruity breath
• Confusion
• Deep or rapid breathing
• Extreme fatigue
• Fainting
• Feelings of malaise
• Increased urination
• Increased (unquenchable) thirst

What to Do If You Have Low Blood Sugar 

Low blood sugar is defined as a blood glucose of less than 70 mg/dL. Immediate treatment of hypoglycemia means consuming 15 grams (g) of carbohydrates and assessing whether your symptoms are improving. What happens next depends on whether you have been diagnosed with diabetes. 

People With Diabetes

The American Diabetes Association suggests that people with diabetes experiencing hypoglycemia follow the 15-15 rule, which is as follows:

• Consume 15 g of carbohydrates to raise your blood sugar.
• Check your blood sugar after 15 minutes.
• If it’s still below 70 mg/dL, have another 15 g serving of carbohydrates.
• Repeat these steps until your blood sugar is at least 70 mg/dL.
• Once your blood sugar is back to normal, eat a meal or a snack to make sure it doesn’t lower again.

Examples of 15 g servings of carbohydrates include:

• Glucose tablets (read package instructions)
• Gel tube, such as Glucogel (which is typically 10 g, so you will need two tubes)
• 4 ounces (one-half cup) of juice or regular soda (not diet or sugar-free)
• 1 tablespoon of sugar, honey, or corn syrup
• Hard candies, jelly beans, or gumdrops (see food label for how many to consume)

People with diabetes should record every low blood sugar event, noting the at-home tested blood glucose and symptoms. If you cannot raise your blood sugar with the 15-15 rule, call your healthcare provider or seek emergency medical care immediately.

Everyone with diabetes on medications that can cause low blood sugar should also have a glucagon emergency kit. In an emergency, it would not be safe for a family member, friend, or bystander to try to pour orange juice in your mouth because it could go in your lungs. A glucagon injection can be used instead to safely raise blood glucose.

Parents of Children With Diabetes

If your child has diabetes and shows symptoms of hypoglycemia, it's important to check their blood glucose level with a glucometer. If this is not possible, it is best to treat them as if they have hypoglycemia by giving them carbohydrates to prevent symptoms from getting worse.

Your child should have a safety plan in place for when they are not in your care, such as when they are at school, friends’ homes, or daycare. The plan should include whom they should talk to if they are not feeling well.

People Without Diabetes

When people without diabetes experience low blood sugar it is called non-diabetic hypoglycemia. This is a rare occurrence and is categorized as either reactive hypoglycemia (which happens within a few hours of eating) or fasting hypoglycemia (which may be related to a disease). Consuming 15 g of carbohydrates in these cases should help with symptoms.

If either of these types of non-diabetic hypoglycemia occurs, you should see your healthcare provider for an assessment of your symptoms, a physical exam, a review of your risk for diabetes, and a check of your blood glucose. Understanding why your blood sugar dipped that low is important to preventing future recurrences and ruling out causes that require medical attention or clinical treatment. 

The possible causes of reactive hypoglycemia include:

• Having prediabetes or being at risk for diabetes
• Stomach surgery, which can make food pass too quickly into your small intestine
• Rare enzyme deficiencies that make it hard for your body to break down food

The possible causes of fasting hypoglycemia include:

• Medications, such as salicylates (a type of pain reliever), sulfa drugs (an antibiotic), pentamidine (treatment for a serious kind of pneumonia), and quinine (treatment for malaria)
• Alcohol use, especially binge drinking
• Serious illnesses, such as those affecting the liver, heart, or kidneys
• Low levels of certain hormones, such as cortisol, growth hormone, glucagon, or epinephrine (adrenaline)
• Tumors, such as a tumor in the pancreas

A Word From Verywell

Nausea can sometimes seem like a minor inconvenience, but it should never be ignored. In people with and without diabetes, nausea can be a sign of low blood sugar, which requires treatment. It may be as simple as consuming carbohydrates, but this isn't always the case. Low blood sugar that cannot be elevated to normal ranges can quickly become a medical emergency. In people with diabetes, nausea can also be a sign that something else is wrong.

Checking your blood sugar is the only way to know for sure if low blood sugar is the cause of your nausea. If your blood sugar is within the normal range, nausea may be the result of medications that need adjustment or severe health conditions like pancreatitis and diabetic ketoacidosis. You should always let your healthcare provider know if you experience nausea to get the best treatment possible and prevent additional health problems.