Signs and Symptoms of Hypoglycemia are different in different age groups. Since hypoglycemia can lead to serious brain-related complications, it is important to identify the signs and symptoms of hypoglycemia.
In certain age groups, specifically in Newborns, Pregnant, and Old Age, these symptoms and signs may be missed.
Furthermore, people with diabetes who develop symptoms of hypoglycemia may be wrongly treated with diabetes medications, further aggravating the situation.
It is very important to know the symptoms and signs of hypoglycemia and hyperglycemia, especially in individuals who have diabetes mellitus.
What is Hypoglycemia?
Strictly speaking, the definition of hypoglycemia is based on plasma blood glucose. It is defined as when the blood glucose drops to less than 70 mg/dl or 4 mmol/L.
However, signs and symptoms of hypoglycemia may develop in some patients when the blood glucose falls to less than 90 mg/dl.
This is true for patients who have long-standing uncontrolled diabetes mellitus. Some of these patients may even notice symptoms of hypoglycemia at a blood glucose of 120 – 150 mg/dl.
On the other hand, many people do not have any symptoms of hypoglycemia unless their blood glucose falls to less than 50 mg/dl.
The variation in symptoms of hypoglycemia at different levels of blood glucose may be due to a number of reasons.
These may include:
- The average daily plasma glucose level is the major deciding factor in developing symptoms of hypoglycemia at specific blood glucose levels.
- Concomitant illnesses such as heart disease patients may develop symptoms earlier.
- Patients on specific medications such as beta-blockers may not have symptoms of hypoglycemia until very late.
- The physical activity of a person. A physically active person may not develop symptoms until very late.
What are the Signs and Symptoms of Hypoglycemia?
Hypoglycemia is associated with a variety of non-specific symptoms. When the blood glucose falls to less than 70 mg/dl, most patients develop mild symptoms of hypoglycemia.
However, as the blood glucose further decreases to 50 mg/dl or less, severe signs and symptoms of hypoglycemia may develop.
Signs and symptoms of hypoglycemia may also vary according to the individual’s age. Newborns, kids, children, adolescents, young adults, and older individuals may have different signs and symptoms of hypoglycemia.
Some patients may not develop symptoms of hypoglycemia even at very low blood glucose levels. This is called hypoglycemia unawareness.
Hypoglycemia unawareness is common in diabetic patients who have diabetic autonomic neuropathy.
These patients may not develop palpitations, sweating, or tremors because their autonomic nervous system is not functioning properly.
Signs and Symptoms of Hypoglycemia:
Adrenergic symptoms develop because of the sympatho-adrenal system activation.
Patients feel hungry, have sweating, anxiety, palpitations and tachycardia, and shakiness, or tremors.
These symptoms develop because the brain receives less glucose. Since glucose is the main nutrient metabolized by the brain, low glucose going to the brain results in the following symptoms and signs:
- Difficulty concentrating
- Blurred vision
- Coma, and
Signs and Symptoms of Hypoglycemia in Newborns:
Hypoglycemia in newborns is defined as neonatal plasma glucose of less than 30 mg/dl during the first 24 hours and less than 45 mg/dl thereafter.
Neonates are especially at risk of hypoglycemia because of their minimal reserves. Furthermore, certain maternal and neonatal conditions may increase their risks of developing hypoglycemia.
Important conditions that may predispose a neonate to develop hypoglycemia include:
- Premature infants
- Birth asphyxia
- Maternal use of alcohol, oral anti-diabetic medicines, quinine, NSAIDs, and other medicines
- Neonatal hepatitis,
- Congenital hypothyroidism
- Congenital adrenal hyperplasia (21-hydroxylase deficiency)
- Liver or renal disease,
- Glycogen storage disorders, and
- Congenital hyperinsulinemia
Symptoms of hypoglycemia in newborns:
During the first few days of life, symptoms of hypoglycemia are extremely important to be watched for, as prolonged hypoglycemia may result in lifelong brain disease.
These symptoms include:
- Poor feeding (this can result in hypoglycemia and can also be a symptom of hypoglycemia)
- An exaggerated Moro Reflex or Startle reflex (The baby cries, spreads its arms, and pulls the arms in adduction in response to a sudden loss of support)
- Hypothermia or hyperthermia
- Cyanosis, and
Other symptoms and signs of hypoglycemia that result in the activation of the adrenergic system include:
- Very fast heartbeats
- Hunger, and
Neuroglycopenic Symptoms of hypoglycemia occur when the glucose levels in the brain are lowered. These symptoms include:
- Mental confusion
- Blurred vision
- Difficulty speaking
- Abnormal movements and ataxia
- Excessive sleep
- Drowsiness and coma
- Stroke, and
Signs and symptoms of hypoglycemia in children:
Older children can have the following symptoms of hypoglycemia:
- Shakiness or Tremors
- Poor feeding
- Coma, and Death
Children who have frequent hypoglycemia may have difficulty concentrating and have a relatively low IQ.
Signs and symptoms of hypoglycemia in adolescents and young adults:
Adolescents and young adults have the same two types of signs and symptoms i.e. Adrenergic and neuroglycopenic signs and symptoms.
Adrenergic Signs and Symptoms of Hypoglycemia:
Activation of the adrenergic system results in:
- Tachycardia or fast heartbeat
- Palpitations and heart-pounding
- Tremors or shakiness
- Hypertension, and Hunger
Neuroglycopenic Signs and Symptoms of Hypoglycemia:
Neuroglycopenic symptoms are due to reduced glucose supply to the brain. When the brain is devoid of glucose which is its major nutrient, it can result in the following symptoms and signs:
- Double or Blurred vision
- Difficulty concentrating
- Irritability and mood swings
- Confusion, drowsiness, and Coma, and
Signs and symptoms of hypoglycemia in older individuals:
Older adults are especially at risk of hypoglycemia because they have poor feeding habits because of loss of dentition, suppressed appetite due to multiple medications, and chronic conditions such as liver, kidney, and heart diseases.
Many patients in this age group are also at an increased risk of hypoglycemia because of poor excretion of oral drugs especially antidiabetic drugs due to compromised kidney and hepatic functions. Certain malignancies can only present with hypoglycemia.
Hypoglycemia in older individuals can cause cardiac arrhythmias resulting in sudden deaths.
Older individuals with frequent mild episodes of hypoglycemia can manifest as frequent falls resulting in fractures. Others may develop a slow cognitive dysfunction and dementia.
Older people have more predominant neurological symptoms than adrenergic symptoms. Also, neurological and autonomic symptoms appear in old age simultaneously without warning.
This is termed “Hypoglycemia Unawareness” or Impaired awareness of hypoglycemia”.
Symptoms of hypoglycemia in old age include:
- Visual disturbances
- Behavioral changes
- Poor functional status
- Reduced quality of life
- Frequent falls and accidents
- Cognitive decline
- Increased risk of Alzheimer’s and Parkinson’s disease
Why hypoglycemia is difficult to diagnose in the elderly [Ref]?
Older individuals may have subtle or no symptoms. Patients may directly present with stroke, visual impairment, and vertigo and the diagnosis may be missed.
Older patients may present with agitation and behavioral changes that may be labeled wrongly as dementia.
Older individuals may have few warning symptoms because of autonomic dysregulation or have atypical presentations such as confusion and delirium.
Lastly, patients may not communicate properly because of dementia and other neurological problems.
Signs and symptoms of hypoglycemia in pregnant women:
Gestational hypoglycemia is more common in pregnant women who are younger than 25 years of age, have a BMI of less than 30 kg/m², and have concomitant medical conditions such as liver or kidney disease.
These women are at an increased risk of developing preeclampsia and eclampsia.
The signs and symptoms of hypoglycemia in pregnant women are the same as in normal adults.
- Blurred vision
- Difficulty concentrating
- Shakiness and tremors
- Palpitations and feeling short of breath
- Nausea and vomiting
- Pale skin
- Tingling Sensation around the lips
- Dizzy spells
- Hypotension, and
Important Questions regarding Hypoglycemia:
Can Hypoglycemia occur without symptoms and signs
Yes. Sometimes patients do not manifest signs and symptoms despite very low blood glucose levels in the blood. This is also called “Impaired awareness of hypoglycemia” or “hypoglycemia unawareness”.
People who do not develop symptoms and signs of hypoglycemia are usually older individuals who have autonomic dysfunction.
In addition, people with recurrent hypoglycemia may also not manifest any signs or symptoms. Lastly, patients who are on certain medications such as Beta-Blockers (propranolol) may have their symptoms and signs masked by the drug.
How do you know if you have hypoglycemia?
It is important to know the symptoms of hypoglycemia, especially if you are diabetic or on certain medications.
People who experience hypoglycemia for the first time get scared and feel as if they are dying.
If you develop sweating, tremors or shakiness, palpitations, weakness, and feeling hungry, always check your blood glucose.
If a glucometer is not available at home, don’t wait to confirm hypoglycemia, just eat something. You can take a pinch of sugar immediately, take two dates or biscuits, or drink a cup of juice to immediately increase your blood glucose levels.
Avoid prolonged hypoglycemia as it can lead to very serious complications including seizures, coma, and death.
Does hypoglycemia cause weight gain?
A single episode or infrequent episodes of hypoglycemia do not cause weight gain. In addition, hypoglycemia occurring in elderly patients because of malnutrition or frailty is also not associated with weight gain.
However, people who have frequent hypoglycemia due to excessive insulin release by the pancreas as occurs in patients with insulinoma, and people who are taking excess exogenous insulin can cause rapid weight gain.
This is also true for patients who are on insulin secretagogues like sulfonylureas.
Can hypoglycemia turn into diabetes?
Hypoglycemia may be a sign of excess insulin release. Sometimes the body increases the pancreatic production of insulin in response to insulin resistance.
In such people, during the development of insulin resistance and a compensatory increase in insulin production, people develop hypoglycemia.
Hypoglycemia in patients with insulin resistance results in weight gain and the vicious cycle continues until the patient becomes diabetic.
So, yes! sometimes frequent hypoglycemia can be an indicator of insulin resistance and diabetes. This state usually lasts for two to five years until the patient has full-blown diabetes.
Can hypoglycemia cause seizures?
Yes. Glucose is the only nutrient the brain requires for proper functioning. Less glucose going to the brain results in various neuroglycopenic symptoms such as weakness, tiredness, pallor, irritability, drowsiness, and seizures.
People who are treated in time may not develop permanent neurological deficits. However, frequent hypoglycemia resulting in frequent episodes of seizures can make the person epileptic.
These patients can then have seizure episodes even when the blood glucose levels are within the range of normoglycemia.
Does hypoglycemia have any effect on blood pressure?
When a person has hypoglycemia, the body responds by increasing adrenergic discharges. The release of adrenaline causes tachycardia and hypertension.
People may develop hypertensive emergency and end-organ damage because of very high blood glucose levels.
Sometimes, especially in pregnant women, dehydrated individuals, and older patients with cardiac disease, hypotension may occur.
Elderly people and those with a low ejection fraction have little cardiac reserves. These patients initially develop hypertension followed by sustained hypotension.
Adrenergic stimulation may also result in angina and heart attack that may be associated with hypertension or hypotension.
What is reactive hypoglycemia?
Reactive hypoglycemia is hypoglycemia occurring within four hours of a meal. Reactive hypoglycemia occurs in individuals who take an excess of dietary refined sugars that are low in fiber and complex carbohydrates.
When the food enters the intestine, it is rapidly absorbed causing an excess or overshooting of insulin production in response to the high glucose load. This causes the blood sugars to go down below the normal ranges.
Reactive hypoglycemia can occur in patients after bariatric surgery when food does not stay in the stomach and goes directly to the intestines and gets absorbed.
This is also called “dumping syndrome“. It can also occur in alcoholics, endocrine disorders such as hypothyroidism, and patients with congenital enzyme deficiencies.
Usually, treatment is not required. However, dietary modification is the treatment of reactive hypoglycemia.
Patients are advised to take a lot of fiber and complex carbohydrates. Alcohol and fizzy drinks should be avoided.
How long can hypoglycemia last?
Hypoglycemia is a rapidly reversible condition. The symptoms can go away in seconds. People becoming unconscious due to hypoglycemia get up in seconds like magic pills.
However, if the underlying cause of hypoglycemia is not treated, recurrent hypoglycemia may occur.
The total duration of hypoglycemia depends on the underlying cause. In addition, hypoglycemia occurring due to a drug overdose is also dependent on the underlying liver and kidney disease.
The half-life of most drugs including insulin is increased in patients with kidney impairment.
The usual estimated time to completely recover from hypoglycemia after a drug overdose is as follows:
Class of Drugs
|Insulin||Rapid-acting insulin (Aspart, GLulisine, Lispro) &
Ultra-rapid-acting insulins (Insulin FiAsp, Lyumjev, Afrezza).
|up to a maximum of four hours|
|Regular insulin||up to a maximum of 6 – 8 hours|
|Intermediate-acting insulin (Insulin NPH)||up to a maximum of 12 – 16 hours|
|Long-acting insulin (Glargine and Detemir)||16 – 22 hours|
|Ultra-long-acting insulin (Degludec)||24 – 36 hours|
|Meglitinides||Repaglinide & Nateglinide||up to four hours|
|Sulfonylureas||Glyburide||Up to 24 – 72 hours|
|Gliclazide||Up to 12 hours|
|Glimepiride||Up to 24 hours|
|Glipizide||8 – 12 hours|
What mimics the symptoms of hypoglycemia?
Symptoms of hypoglycemia are very non-specific and can mimic any disease. Patients need to be investigated for any of the following conditions if they have symptoms of hypoglycemia with normal blood glucose levels:
Hyperthyroidism can present with sweating, palpitations, tremors, and shakiness
Sepsis and anaphylaxis can manifest as hypotension, tachycardia, pallor, and sweating
- Heart failure:
Heart failure can manifest as weakness, shortness of breath, tachycardia, palpitations, and hypotension
Asthma and the use of asthma medications can manifest as heart-pounding, tachycardia, tremors, and hypertension
Anxiety can have symptoms similar to hypoglycemia. These include sweating, tachycardia, palpitations, hunger, anxiety spells, tremors, shakiness, and irritability
Pheochromocytoma has all the adrenergic symptoms as in patients with hypoglycemia. These include tachycardia, hypertension, sweating, anger, and irritability.
Stroke patients can have weakness, drowsiness, and hypertension.
- Heart attack:
Heart attack or myocardial infarction can have similar symptoms as hypoglycemia. These include heart pounding, sweating, irritability, and drowsiness.
- Syncope and Vertigo:
Syncope and vertigo are very common. Patients may fall down during a syncopal attack and develop other complications too.
Epilepsy (Occasionally patients with hypoglycemia can have seizures that may be misdiagnosed as epilepsy)
What are the symptoms of Hypoglycemia vs. Hyperglycemia:
It is important to differentiate between the symptoms of hypoglycemia and hyperglycemia as the treatment of both conditions is totally the opposite.
Some of the common symptoms are mentioned below:
Symptoms of Hypoglycemia
Symptoms of Hyperglycemia
Excessive thirst and hunger,
Nausea and vomiting,
Lethargy and weakness,
Shortness of breath,