Hypoglycemia

Hypoglycemia is a decrease in blood glucose levels below 70 mg/dL (milligrams per deciliter). The consequences for the body can potentially be severe, since glucose is responsible for providing the body with the energy it needs to function properly.

Although it is usually associated with diabetes, a metabolic disease in which the body does not properly regulate the amount of glucose in the blood, because this is its main cause, it may also occur as a consequence of other conditions or due to the intake of certain medications.

The different severity levels of hypoglycemia are defined by the blood glucose values which, in adult patients, are:

• Level 1: mild or moderate hypoglycemia in which glucose levels are between 70 and 54 mg/dL.
• Level 2: clinically significant hypoglycemia causing glucose levels below 54 mg/dL.
• Level 3: severe hypoglycemia in which the state of consciousness is altered, meaning that the patient is unable to care for themselves.

Hypoglycemia in newborn babies (neonatal hypoglycemia), which is common during the first days after birth, is established at values below 45 mg/dL.

The prognosis for hypoglycemia is usually good if appropriate treatment is received promptly, since in most cases it resolves without causing complications. However, severe hypoglycemia is a medical emergency that must be treated immediately, so it is important to learn to recognize the symptoms in order to seek emergency care if it occurs.

Symptoms

The most characteristic symptoms of hypoglycemia vary according to the severity level:

• Mild hypoglycemia:
  • Pallor.
  • Sweating.
  • Tremors.
  • Headache.
  • Hunger.
  • Nausea.
  • Arrhythmia: irregular heartbeat.
  • Tachycardia: accelerated heart rate.
  • Fatigue.
  • Lightheadedness.
  • Dizziness.
  • Numbness of the lips, tongue, or cheek.
  • Irritability.
  • Anxiety.
• Moderate hypoglycemia:
  • Disorientation.
  • Inability to carry out routine tasks.
  • Loss of coordination.
  • Difficulty speaking.
  • Blurred vision.
  • Tunnel vision: peripheral vision is lost and only central vision remains.
  • If it occurs during sleep, nightmares.
• Severe hypoglycemia:
  • Loss of consciousness.
  • Seizures.

Neonatal hypoglycemia presents the following symptoms:

• Pale or bluish skin.
• Breathing problems:
  • Apnea: temporary interruption of breathing.
  • Rapid breathing.
  • Grunting during breathing.
• Irritability.
• Floppy muscles.
• Vomiting.
• Tremors.
• Chills.
• Low body temperature.
• Poor feeding or refusal to feed.
• Seizures.

Causes

In most cases, hypoglycemia occurs as the body’s response to external factors that result in a mild decrease in glucose levels:

• In diabetic patients: in patients who do not produce enough insulin (the hormone that controls glucose metabolism and allows glucose to enter cells so they can convert it into energy) or whose body is unable to use the insulin it produces properly, hypoglycemia is usually due to:
  • Imbalance between the insulin dose administered as treatment and the amount of calories consumed.
  • Excessive physical exercise while maintaining the same insulin dose.
  • Alcohol consumption.
  • Medications that enhance the effect of antidiabetic drugs:
    • Salicylates, such as aspirin, which relieve pain, reduce fever, and decrease inflammation.
    • Clofibrates, which reduce triglycerides and LDL cholesterol.
    • Phenylbutazone, which relieves chronic pain.
    • Sulfinpyrazone, which prevents uric acid reabsorption, thereby reducing its levels in the blood.
• In non-diabetic individuals, hypoglycemia is usually caused by:
  • Excessive alcohol consumption.
  • Hepatitis: inflammation of the liver usually caused by a viral infection.
  • Cirrhosis: formation of scar tissue in the liver.
  • Kidney disease.
  • Heart disease.
  • Severe infection.
  • Malnutrition.
  • Starvation: lack of food intake.
  • Insulinoma: pancreatic tumor causing excessive insulin production.
  • Tumors in the pituitary gland or adrenal gland causing hormonal deficiencies.
  • Pregnancy: pregnant women are more prone to low blood sugar when fasting or when the stomach is empty due to hormonal changes.

Reactive or postprandial hypoglycemia, which occurs on rare occasions, appears around 2 to 3 hours after eating certain foods. Some of the causes include:

• After a meal rich in carbohydrates, excessive insulin is released. As a result, blood glucose levels drop excessively.
• Excessive sensitivity to insulin activity.
• Alterations in pancreatic response.
• Dumping syndrome: a condition affecting patients who have undergone bariatric surgery to reduce stomach capacity. After the procedure, food passes too quickly into the intestine, sometimes without being completely digested. This condition may cause carbohydrates to be absorbed earlier than normal and, consequently, produce insulin spikes.
• Chronic stress: alters hormone levels, affecting blood sugar regulation.
• Imbalances in the production of glucagon or cortisol, two counterregulatory hormones responsible for counteracting the effects of insulin in order to prevent hypoglycemia.

Hypoglycemia in babies is usually caused by:

• Excess insulin.
• Low glucose reserves in the body.
• Very high energy consumption.

Risk factors

The risk of developing hypoglycemia increases when any of the following factors are present:

• Diabetic patients treated with exogenous insulin, especially if there is a dosing error.
• Skipping meals.
• Irregular meal schedules.
• Inadequate carbohydrate intake.
• Being older than 65 years.
• Kidney failure.
• Liver failure.
• Heart disease.
• History of diabetes.
• Malabsorption of food.

Risk factors for neonatal hypoglycemia include:

• Prematurity.
• Severe infections.
• Need for oxygen after delivery.
• Diabetic mother.
• Slow growth in the womb.
• Larger or smaller than normal size for gestational age.

Complications

When hypoglycemia is not properly treated, it may lead to the following complications:

• Weakness.
• Disorientation.
• Dizziness.
• Falls.
• Accidents.
• Injuries.
• Dementia.
• Seizures.
• Coma.
• Death.

In babies, the most notable complications are brain damage, mainly cerebral palsy, and learning disabilities.

What specialist treats hypoglycemia?

Hypoglycemia is treated within the specialties of Endocrinology and Nutrition, Family and community medicine, or Emergency department. In neonates, the Pediatrics specialist is involved.