Home Symptoms Hypoglycemia (low blood sugar) : Signs, Treatment, Risks

Hypoglycemia (low blood sugar) : Signs, Treatment, Risks

by Josephine Andrews
Published: Last Updated on 372 views

Hypoglycemia is the medical term for low blood sugar. Blood sugar levels that are too low are particularly dangerous for the brain because it relies on sugar as a source of energy. The body reacts to the deficiency with stress symptoms such as sweating, heart palpitations and tremors. Severe hypoglycaemia can even be life-threatening. Diabetics in particular are repeatedly affected by this. Read everything you need to know about the causes, symptoms and treatment of hypoglycemia.

quick overview

  • What is hypoglycemia? Hypoglycaemia, i.e. a drop in the sugar level in the blood below 45 mg/dl
  • Symptoms: trembling, tachycardia, pale skin , cravings , possibly nausea, headaches, difficulty concentrating
  • Causes: Hypoglycemia occurs when the body uses more glucose than is available. Possible triggers are, for example, diabetes mellitus and other metabolic disorders, hormone disorders, intolerances, medication.
  • First aid: The blood sugar level can often be brought back to normal with sweetened drinks or glucose . In severe cases, an infusion may be necessary.
  • Dangers: Severe hypoglycaemia can lead to seizures, paralysis, respiratory and circulatory disorders and unconsciousness. In extreme cases, severe hypoglycaemia can be fatal.

Hypoglycemia: description

Hypoglycemia is when the blood sugar (glucose) concentration falls below 45 milligrams per deciliter (mg/dl).

Normally, in healthy people, various hormones ensure that the glucose concentration in the blood stays within a certain range. In the fasting state it is between 70 and 100 mg/dl.

If the blood sugar falls too far, various symptoms appear such as restlessness, cravings, tremors and tachycardia, later also confusion and finally coma .

When hypoglycemia becomes noticeable varies from person to person. In some people, the signs of hypoglycaemia appear at values ​​well above 50 mg/dl, while others do not feel any symptoms even at lower values.

Prevent hypoglycaemia

Diabetics are more likely to suffer from hypoglycemia. Unfortunately, they feel the symptoms of low blood sugar late or not at all. It is all the more important that those affected know in which situations the blood sugar levels could be too low.

In special training courses – carried out either by a doctor or a diabetes consultant – diabetics learn how to recognize impending hypoglycaemia in good time and how to react to it correctly.

Hypoglycemia: symptoms

Low blood sugar means great stress for the organism. Above all, the body has to ensure the supply of the brain, which is absolutely dependent on glucose as an energy source. It also accelerates glycogenolysis (breaking down glycogen into glucose) and sugar formation (gluconeogenesis). This is achieved by the adrenal glands increasing the release of the stress hormones cortisol and adrenaline into the blood.

As a result, the typical symptoms of hypoglycaemia develop:

  • dizziness
  • inner restlessness and irritability
  • sudden sweating (cold sweat)
  • Tremble
  • skin pallor
  • tachycardia and rise in blood pressure
  • Cravings, sometimes nausea and vomiting

Symptoms of severe hypoglycaemia

The brain’s undersupply of glucose can also cause neurological symptoms as hypoglycaemia progresses. Signs are then:

  • headache
  • tiredness and weakness
  • Difficulty concentrating and disorientation
  • speech disorders
  • Discomfort, rarely even signs of paralysis
  • unconsciousness, fainting
  • seizures
  • coordination problems

Low blood sugar: symptoms during sleep

Many diabetics are afraid of slipping into hypoglycaemia while sleeping. In fact, the hormonal counter-regulation does not work as well at night as it does when we are awake. Hypoglycemia symptoms at night are the same as during the day. However, the sleeping person usually doesn’t notice anything about it, but only sleeps badly. So if you feel inexplicably exhausted during the day, you should talk to your doctor about it. There may be a drop in blood sugar at night. Then it can help to adjust the dosage of the diabetes medication (especially the basal insulin ), eat a little something before going to bed and avoid late-night exercise and alcohol.

Hypoglycemia: causes and possible diseases

Low blood sugar always occurs when the body uses more glucose than it has available. Normally, a drop in blood sugar levels causes hormones to cause the release of glucose from stores (i.e. the breakdown of glycogen), causing blood sugar levels to rise again. However, this mechanism can be disrupted – either because the hormonal regulation is not working or because the glycogen stores are empty.

Even if the blood sugar is used up very quickly, e.g. B. by physical exertion, the result is sometimes hypoglycaemia. Sport with diabetes is not dangerous if you eat enough.

There are many causes of hypoglycemia. However, diabetics are most affected. However, other metabolic disorders, hormone disorders and liver diseases are often the triggers for hypoglycaemia.

Hypoglycemia in diabetics

The fact that people with diabetes mellitus slip into hypoglycaemia relatively often seems illogical at first. Because with diabetics, the problem is actually a permanently elevated glucose level in the blood, because the blood-sugar-lowering hormone insulin either no longer works properly or is produced in too small quantities. So why can diabetics also have too low blood sugar?

Medication administration errors

Mistakes in therapy are usually (but not always) to blame. Diabetes is treated with blood-sugar-lowering drugs—oral blood-sugar-lowering drugs and/or insulin shots.

In the case of oral diabetes medication, the so-called sulfonylureas (such as glibenclamide ) in particular can cause hypoglycaemia in the event of an overdose. The drugs stimulate the pancreas to release more insulin into the blood.

Insulin injections are usually self-administered by diabetics. They always have to adjust the dosage to how much carbohydrate a planned meal contains and how physically active they are. However, if patients inject too much insulin (for example, because they overestimate the amount of carbohydrates in a meal or are unusually physically active), hypoglycemia can result.

In the case of insulin, however, not only the amount administered is relevant, but also the amount of time before food intake it is injected. If it is injected too early or if gastric emptying is delayed due to excess fat or protein, the blood sugar level will drop before new glucose enters the blood. Hypoglycaemia can also occur if a diabetic injects mealtime insulin but then doesn’t eat anything.

It is also important that the patient always injects the insulin into the subcutaneous fatty tissue and not accidentally into the muscle. Because from there the hormone would possibly get into the bloodstream too quickly .

Hypoglycaemia caused by alcohol

Some factors can further lower the level of glucose in the blood. Alcohol, for example, decreases the release of glucose from the liver, increasing the risk of hypoglycemia.

Hypoglycaemia: sports

Physical exertion and sport also lower the blood sugar level and thus the need for insulin or blood sugar-lowering tablets. The result is sometimes hypoglycaemia.

Hypoglycaemia: thyroid

The thyroid may also play a role. If you have an underactive thyroid (which has not yet been discovered) , hypoglycaemia can “accidentally” develop. Because the malfunction improves the insulin sensitivity of the cells, so that the blood sugar gets into the cells faster.

Excessive insulin production

In type 2 diabetes mellitus, insulin production is often elevated at the beginning of the disease. The body tries to compensate for the reduced effect of the hormone. After eating, too much glucose is transported into the cells due to the excess amount of insulin. This phenomenon is known as postprandial hypoglycemia.

hypoglycemia unawareness

A significant risk factor for the occurrence of severe hypoglycaemia is the so-called hypoglycaemia perception disorder. Here the patient lacks the warning symptoms that usually appear before the classic symptoms (flight of thoughts, logorrhea, difficulty finding words, irritability, double vision and other visual disturbances, headaches, anxiety, drowsiness, coordination difficulties, nausea, headaches, restricted consciousness and actions, unconsciousness, convulsions). This phenomenon is understood as the body’s adaptation to recurring (slight) or permanent hypoglycemia with a low HbA1c value. This condition can only be prevented by consistently avoiding – even mild – hypoglycaemic conditions.

Hypoglycaemia without diabetes

Although it usually occurs in connection with diabetes, hypoglycaemia without diabetes is also possible.

Hormonal causes of hypoglycemia

Various hormonal imbalances can trigger low blood sugar, which then usually occurs together with other symptoms. For example, hypoglycemia can be due to an underactive adrenal cortex . This produces various hormones, including cortisol and adrenaline. Both help the body counteract hypoglycemia. If hormone production is disturbed in the adrenal glands , this effect does not occur.

The adrenal cortex does not work independently, but is controlled by the pituitary gland ( pituitary gland ). If their function is restricted, the adrenal cortex also produces fewer hormones. In addition, TSH and somatotropin are formed in the pituitary gland – two hormones that directly or indirectly increase blood sugar levels. An underactive pituitary gland is therefore often associated with hypoglycemia.

Insulinomas are rare, mostly benign tumors in the pancreas that produce insulin in excess and uncontrollably. Those affected often suffer from initially inexplicable hypoglycaemia.

Glucagon is particularly important for increasing the concentration of glucose in the blood. However, a sole glucagon deficiency as the cause of hypoglycaemia rarely occurs.

Hypoglycemia from fasting and dieting

Poor nutrition can also promote low blood sugar – especially extreme fasting and dieting that are too strict. But if you skip a meal, you don’t have to worry about slipping into a dangerously low blood sugar level. The body normally has enough reserves to make up for a temporary lack of glucose. However, if there are additional risk factors such as previous alcohol consumption or taking certain medications, you should ensure that carbohydrates are replenished in good time.

Other non-diabetic causes of hypoglycemia

There are many other triggers of hypoglycemia, for example:

  • severe liver diseases , in which the breakdown of glycogen and the formation of glucose are disturbed. The body cannot compensate for low blood sugar.
  • Disorders of the carbohydrate metabolism : This includes, for example, diseases in which the build-up of glycogen and thus the storage of glucose is disturbed (glycogenoses). A fructose intolerance (fruit sugar intolerance) often leads to low blood sugar.
  • Too much sugar in one go: If you eat a lot of sugar at once, the body reacts by releasing a large amount of insulin. This can result in an excess of the hormone, which then lowers the blood sugar level too much – so-called reactive hypoglycaemia occurs. This is how hypoglycaemia can occur in healthy people.
  • Dumping syndrome: This phenomenon occurs mainly in people who have had part of their stomach removed. The food pulp then suddenly reaches the intestines in large quantities . As a result, large amounts of glucose build up in the blood, which leads to excessive insulin release and after a few hours (hence the exact term “late dumping”) to hypoglycemia.
  • Disturbed food intake: There are diseases due to which the body cannot absorb enough glucose from the intestine. An example of this is celiac disease – a form of gluten intolerance that damages the intestinal mucosa.
  • Medications such as certain sulfonamide antibiotics and some beta-blockers can also cause hypoglycaemia. Normally, however, the use of these drugs alone does not cause hypoglycemia. This only occurs in conjunction with other risk factors.
  • Chronic alcohol abuse: On the one hand, alcoholics are often malnourished, on the other hand, the alcohol itself causes a drop in blood sugar levels.
  • Diabetes during pregnancy: The fetus gets used to the high glucose levels in the mother’s blood and produces more insulin. After the birth , this insulin excess leads to low blood sugar in the child for a few days.

Hypoglycemia: What to do if you have low blood sugar?

Slight hypoglycaemia in non-diabetics (with dizziness, paleness, tachycardia, but full consciousness) can often be remedied by simple measures: Give the affected person glucose and/or sweetened drinks (e.g. sweetened tea, cola) and ensure that his or her is calm Vicinity. He then usually recovers quickly. If not, call the emergency services.

If the hypoglycaemia is more severe and the affected person has lost consciousness, you must place them in the recovery position and call the emergency services immediately!

First aid for diabetics

Hypoglycemia is particularly common in diabetics. Many are prepared for such an emergency by always having a blood glucose meter to hand. If there are signs of hypoglycaemia, the first thing to do is measure the blood sugar level to determine the extent of the glucose deficiency. The further procedure depends on the measurement result:

First aid for mild hypoglycaemia (40 – 50 mg/dl)

Diabetics can still help themselves if they have a slight hypoglycemia:

  • Eat some dextrose (about 15-20 grams is recommended); repeating after 15 minutes if blood glucose persists is recommended
  • Alternatively, you can drink a glass (approx. 200 ml) of sweetened tea, fruit juice, cola or lemonade (no light products, of course!).
  • Measure the blood sugar level again after 15 minutes. If it is still not higher than 50 to 60 mg/dl, you should consume glucose or sweetened drinks again.
  • If your blood sugar level has improved, you should stabilize it by eating a small carbohydrate-rich meal, e.g. E.g. fruit, bread, sweetened yoghurt.

First aid for severe hypoglycaemia (< 40 mg/dl)

In the case of severe hypoglycaemia, diabetics are dependent on outside help from first aiders. If the diabetic is still conscious , the first aid looks similar to the one above: supply of approx. 30 grams of carbohydrates that can be used quickly (preferably in the form of glucose or sugar-sweetened drinks), blood sugar control, stabilization of the blood sugar level with a small meal; a repeat after 15 minutes is recommended if blood glucose remains low.

If the diabetic is unconscious , you should react as follows:

  • Call an ambulance immediately.
  • Place the unconscious person in the recovery position.
  • Remove bits of food or loose dentures from the victim’s mouth.
  • If available, inject 1 milligram of glucagon under the skin or into a muscle (eg, thigh muscle).
  • If the hypoglycaemic regains consciousness, give them glucose or sweet drinks.

Caution: Never try to give anything down the throat to an unconscious person! There is a risk of suffocation!

Hypoglycemia: what does the doctor do?

Profound hypoglycemia is a potentially life-threatening condition that should always be treated by a doctor. Because if it continues to progress, the low blood sugar eventually leads to what is known as hypoglycemic shock . The victim then becomes unconscious and may fall into a coma. You should therefore always call an ambulance in the event of impaired consciousness with suspected hypoglycaemia.

medical history (anamnesis)

Because the symptoms of hypoglycemia can also occur with other diseases, a doctor will first obtain important information about the patient’s history (anamnesis). For example, he asks about existing underlying diseases (such as diabetes), about the use of medication and previous alcohol consumption.

blood glucose measurement

In addition, a quick measurement of the blood sugar level is important. Portable devices are available for this purpose, which can reliably determine the current sugar value within a few minutes from a small drop of blood.


If the suspicion of hypoglycemia is confirmed, the doctor administers glucose to the patient. As long as he is still conscious and able to speak, he can take it in the form of glucose or sugary drinks. If nothing else is available, sweets, such as candy, will also do. However, depending on the composition, it then takes longer for the blood sugar level to rise.

glucose infusion

In the case of severe hypoglycaemia with disturbances of consciousness or in the case of nausea and vomiting, the doctor must administer the glucose as an infusion directly into the vein. During the infusion, he regularly checks the patient’s blood sugar levels to avoid overdosing.

glucagon administration

Another way to raise blood sugar levels quickly is to give glucagon. However, this only works if the glycogen stores are not empty, i.e. the patient has not fasted for a long time or been physically active. Glucagon also does not work in patients with disorders of glycogen metabolism (glycogenosis) or after extensive alcohol consumption.

Important investigations

Various examinations help the doctor to find out the causes of the symptoms. These include, for example:

  • special X-ray examination of the bile ducts, gallbladder and ducts of the pancreas (ERCP)
  • H2 breath test
  • urine test

Hypoglycemia: the dangers of low blood sugar

Severe hypoglycaemia (blood sugar < 40 mg/dl) can have serious consequences. There is a risk of seizures and paralysis, respiratory and circulatory disorders and unconsciousness. Sometimes such severe hypoglycemia ends in a coma.

When is hypoglycemia fatal?

There is no clear threshold from which hypoglycaemia ends in death. The decisive factors are the individual constitution and the duration of the hypoglycaemia.

However, fatal outcomes from hypoglycemia are quite rare. According to statistics, severe hypoglycaemia does not occur in even one in 100 type 2 diabetics per year. However, they are more common in the much rarer type 1 diabetes.

People over the age of 70, patients with kidney failure, patients who have to take a lot of medication and people who eat poorly are particularly susceptible to severe hypoglycaemia and its consequences.

This is how the body regulates blood sugar

Every cell in our organism has to be supplied with energy. The body gains this energy by utilizing various nutrients. The most important of these energy carriers is the sugar molecule glucose. Carbohydrates that humans take in with food are nothing more than such sugar compounds. While still in the digestive tract, most of these are broken down into glucose, which is then absorbed into the bloodstream.

The body also has other ways of generating energy, for example by breaking down fat and protein. But the direct supply of carbohydrates is very important, especially for a quick supply of energy.

There are also cells that obtain their energy exclusively from the breakdown of glucose (glycolysis). These primarily include the nerve cells in the brain and spinal cord. They are therefore life-threatening in the event of hypoglycaemia.

How is blood sugar controlled?

It is important that the blood sugar level remains constant within a narrow range, i.e. neither too low nor too high. With hypoglycaemia, the body lacks the necessary energy supply. Excessively high glucose concentrations, on the other hand, lead to a wide variety of damage over the long term, especially to blood vessels and nerve cells.

Control hormones: insulin and glucagon

Blood sugar levels are normally controlled automatically by hormones, primarily insulin and glucagon:

  • Insulin is the only hormone that can lower the level of sugar in the blood. It is formed by the pancreas and ensures that glucose is absorbed in muscle, fat and liver cells. In muscle and liver cells, numerous glucose molecules combine to form so-called glycogen, the storage form of sugar. The body releases insulin mainly after eating, because then larger amounts of glucose get from the digestive tract into the blood.
  • Glucagon is the antagonist of insulin. It causes blood sugar levels to rise by causing glycogen to be broken down into individual glucose molecules (glycogenolysis). These then pass out of the cells into the blood. In addition, glucagon promotes gluconeogenesis, i.e. the new production of glucose from protein building blocks ( amino acids ).

Other hormones that increase blood sugar levels are adrenaline, cortisol, the growth hormone somatotropin (STH) and the thyroid hormone thyroxine.

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