Hypoglycemia (low blood sugar): What you should know

Hypoglycemia refers to the reduced blood sugar levels, or glucose levels. Hypoglycemia is not a disease but can be an indicator of a health issue.

All the cells in the body, including the brain, need to work with energy. Glucose lends the body strength. Insulin, a hormone, enables the absorption and function of the cells.

Low blood sugar symptoms include hunger, trembling, heart racing, nausea and sweating. That can lead to coma and death in extreme cases.

Hypoglycemia may occur under various circumstances, but it most frequently occurs as a reaction to medication, such as insulin. Diabetes sufferers use insulin to control high blood sugar.

What is hypoglycemia?

Faintness can be an early sign of hypoglycemia
Faintness can be an early sign of hypoglycemia

Hypoglycemia happens when blood does not contain enough glucose, or sugar.

The National Diabetes and Digestive and Kidney Disease Institutes (NIDDK) states that symptoms typically arise when blood sugar levels are below 70 mg / dL per deciliter.

But this number can vary from person to person.


People with mild hypoglycemia may experience the following early symptoms:

  • hunger
  • tremor or trembling
  • sweating
  • shaking
  • a pale face
  • heart palpitations
  • rapid or irregular heart rate
  • dizziness and weakness
  • blurred vision
  • confusion

Severe hypoglycemia may involve:

  • weakness and tiredness
  • poor concentration
  • irritability and nervousness
  • confusion
  • irrational or argumentative behavior and personality changes
  • tingling in the mouth
  • coordination problems


If a person does not take action, they may have:

  • difficulty eating or drinking
  • seizures
  • a loss of consciousness
  • coma

Severe hypoglycemia can be life-threatening.

An individual who experiences hypoglycemia on a regular basis may become unaware that it is occurring or getting worse. They won’t know the warning signs, and that can lead to serious problems, probably fatal.

Hypoglycemia is also a sign of inadequate diabetes management.


Hypoglycemia can occur for various reasons.

Blood sugar regulation

The digestive system breaks down dietary carbohydrates. One of the molecules that this produces is glucose, the principal source of energy for the body.

When we feed, glucose gets into the bloodstream. However, glucose requires insulin — a hormone released by the pancreas — before it can get into a cell. In other words, even though there’s plenty of glucose available, if there’s no insulin, a cell will starve of energy.

The pancreas releases the right amount of insulin after feeding, gradually to transfer the glucose in the blood into the cells. Blood sugar levels decrease as glucose reaches the cells.

Any extra glucose, in the form of glycogen, or processed glucose, goes into the liver and muscles. This glucose can be used later by the body when it requires more energy.

Insulin is responsible for restoring elevated levels of blood sugar to normal.

When glucose levels fall because an person has not eaten for a while, glucagon — another hormone — is secreted by the pancreas which triggers the breakdown of stored glycogen into glucose.

Then, the body releases the glycogen into the bloodstream, taking back glucose levels.

Hypoglycemia and diabetes

A young man checking his blood pressure
Testing blood sugar regularly can help those with diabetes to prevent hypoglycemia.

Type 1 and type 2 diabetes both require an insulin problem.

Type 1 diabetes: damage to the cells usually producing insulin means the body is unable to produce insulin.

Type 2 diabetes: The cells of the body do not respond to insulin properly, or the pancreas does not release enough insulin.

The cells are not getting enough energy in both forms of diabetes.

Those with type 1 diabetes and certain those with type 2 tend to take insulin or other drugs to reduce their blood sugar levels.

If the dosage is too high, blood sugar levels can drop too much, resulting in hypoglycemia.

Hypoglycemia can also occur if the person is exercising more than normal or eating not enough.

To have too much insulin in your body a person does not need to increase their dose. It could be that the insulin they took in that moment was more than their body required.

All insulin and two other drugs can lead to hypoglycemia according to the NIDDK. Those medicines are meglitinides and sulfonylureas.

Hypoglycemia in children: Pediatric ketotic hypoglycemia

Some children experience pediatric ketotic hypoglycemia, which includes low levels of blood sugar and high levels of a substance called ketones.

Doctors do not know exactly why this happens, but causes may include:

  • metabolism problems that the child was born
  • conditions that lead to excess production of certain hormones

Symptoms usually appear after the age of 6 months and disappear before adolescence.

They include:

  • fatigue
  • headaches
  • pale skin
  • confusion
  • dizziness
  • irritability
  • mood changes
  • clumsy or jerky movements

When a child has some of the above signs or symptoms they will see a doctor at the earliest possible opportunity.

Insulin autoimmune syndrome

Another potential cause of hypoglycemia is autoimmune insulin syndrome, a rare disorder that occurs when insulin is targeted by the body’s immune system, mistaking it for an unwanted substance.

According to the Genetic and Rare Diseases Information Center (GARD), signs begin to occur unexpectedly. After a few months, they sometimes go away but occasionally they come back again.

The effects usually can be managed by medication.

Symptoms and diagnosis related to other conditions are close to those for hypoglycemia.

Other causes

People may experience hypoglycemia for other reasons.

Some medications: Quinine, a drug that prevents malaria, can trigger hypoglycemia. High doses of salicylates, used to treat rheumatic disease, or propranolol for hypertension (high blood pressure) may also cause blood sugar levels to drop. It can also happen when a person takes diabetes medication without having diabetes.

Alcohol consumption: Drinking large amounts of alcohol can cause the liver to stop releasing stored glucose into the bloodstream.

Some liver diseases: Drug-induced hepatitis can lead to hypoglycemia, because it affects the liver.

Kidney disorders: People with a kidney disorder may have problems excreting medications. This can result in low blood sugar levels.

Not eating enough: People with eating disorders, such as anorexia nervosa, may experience dramatic falls in their blood sugar levels. Fasting or missing a meal may lead to low blood sugar levels.

Insulinoma: A tumor in the pancreas can cause the pancreas to produce too much insulin.

Increased activity: Increasing levels of physical activity can lower blood sugar levels for some time.

Endocrine problems: Some disorders of the adrenal and pituitary glands can lead to hypoglycemia. This is more common in children than adults.

Reactive, or postprandial, hypoglycemia: The pancreas produces too much insulin after a meal.

Tumors: Rarely, a tumor in a part of the body other than the pancreas can cause hypoglycemia.

Severe illness: Some diseases, such as cancer, can affect many different organs, including the pancreas. This can lead to hypoglycemia.


Anyone who feels the hypoglycemic symptoms but doesn’t understand should see a doctor.

The doctor will probably:

  • order a blood test to measure blood sugar levels
  • ask about symptoms, and whether they improve after blood sugar levels return to normal
  • check the patient’s medical history and any medications they are taking
  • ask the person about their alcohol consumption

Whipple’s triad

A series of three criteria, known as Whipple’s criteria, can indicate that a pancreatic tumor is responsible for symptoms.

Whipple’s three Triad parameters are as follows:

  • Signs and symptoms indicate hypoglycemia.
  • When symptoms occur, a blood test shows low plasma glucose levels.
  • When glucose rises to normal levels, symptoms go away.

A person may not have symptoms at the time of a doctor’s visit. The doctor can ask them to fast, normally overnight, for a time. It allows for hypoglycemia, so that a diagnosis can be made by the doctor.

Some people will need to spend time in the hospital for longer, and quickly.

When signs occur after eating, then after eating, they may need another glucose test.

Read more about pancreatic cancer here.


woman drinking orange juice to treat hypoglycemia

Anyone who notices symptoms of hypoglycemia should eat immediately:

  • a glucose tablet
  • a sugar lump
  • a candy
  • a glass of fruit juice

This can produce fast results. They should be eating slower-release carbohydrates afterwards, such as cereals, bread, rice, or fruit.

The next step is to seek treatment for any underlying cause,

For diabetes

A diabetes patient should test their blood glucose and treat the hypoglycemia, then wait 15–20 minutes and test their blood sugar again.

If there is still low blood glucose levels the individual will repeat the procedure. They should eat some glucose, wait about 15–20 minutes, then look again at their blood sugar.

People with diabetes must keep to eating regularly. This would help to regulate blood glucose levels

Severe symptoms

If symptoms are serious and the patient is unable to cure himself, someone else may have to apply sugar, treacle, jelly or Glucogel to the inside of the cheeks and then rub the outside of the cheeks gently.

Within 10–20 minutes the person should begin feeling better.

Losing consciousness

If the person loses consciousness, someone should place them in the role of recovery, and a qualified health care provider should administer a glucagon injection.

If this is not possible, someone will call for emergency services to take the person to a hospital’s emergency room.

It is necessary not to put food or drink into an unconscious person’s mouth, because it could obstruct the airways.


Cooked rice
Complex carbohydrates, such as brown rice, can help prevent hypoglycemia.

A variety of dietary factors have the ability to help regulate hypoglycemia.

Low-sugar diet: It is good to provide small intakes of simple sugars and large intakes of complex carbohydrates. It takes longer to digest complex carbs and this can help avoid glucose swings.

Small, frequent meals: eating small meals at least three times a day will help reduce levels of blood sugar.

For people with hypoglycemia, some people have suggested a low-sugar, high-protein diet, but this may improve glucose tolerance and add extra fat to the diet.

Hypoglycemia vs. hyperglycemia

Hypoglycemia and hyperglycemia are also linked to levels of blood sugar but they are not the same.

Hypoglycemia: The blood contains too little glucose, below 70 mg / dL.

Hyperglycemia: Glucose levels are too high when fasting, over 126 mg / L, or 200 mg / dL 2 hours after feeding.


In most people, eating regular meals which include complex carbohydrates may prevent hypoglycemia.

People at risk of hypoglycemia due to a medical condition should also follow a treatment plan:

Follow a treatment plan: It is important to follow the doctor’s instructions and seek help if symptoms change.

Checking blood glucose levels: Those at risk should periodically monitor their blood sugar levels and be able to identify the symptoms.

Alcohol: Follow the normal limits of alcohol prescribed by a doctor, and avoid alcohol without food.

Exercise: Before exercising, eat a snack high in carbohydrates and be mindful of how exercise can affect blood sugar levels.

Take caution when ill: Vomiting can, for example, prevent the body from consuming adequate energy.

Being ready: Bring a fruit juice bottle or a chocolate bar in case of symptoms.

Letting people know: anyone susceptible to low blood sugar should let friends, employers, and members of the family know.

Medical ID: Carrying an ID or medical bracelet would enable healthcare providers, emergency responders and others to know what to do sooner.


Hypoglycemia can lead to symptoms including dizziness, weakness and a loss of consciousness in extreme cases.

Persons with multiple medical conditions, including diabetes, may be at elevated risk of hypoglycemia.

Knowing how to identify the symptoms is critical, and being prepared to take action if they occur.

Obianuju Chukwu

She has a degree in pharmacy and has worked in the field as a pharmacist in a hospital. Teaching, blogging, and producing scientific articles are some of her interests. She enjoys writing on various topics relating to health and medicine, including health and beauty-related natural treatments, the nutritional worth of various foods, and mental wellness.