The following symptoms and complaints may indicate hypoglycemia (low blood sugar):
The signs of hypoglycemia depend on the degree of hypoglycemia. According to the severity of hypoglycemia, three groups are distinguished:
Autonomic signs (synonym: adrenergic signs). These result from a reactive release of adrenaline. These signs include:
- Paleness
- Ravenous hunger
- Palpitations (heart palpitations)
- Sweating
- Tachycardia (heartbeat too fast: > 100 beats per minute).
- Tremor (shaking)
Neuroglycopenic signs: These signs result from glucose deficiency in the central nervous system (CNS) (usually appearing only at blood glucose concentrations < 50 mg/dl/2.75 mmol/l). Glycopenia affects numerous neuronal functions and manifests as follows:
- Atypical behavior (aggressiveness; anxiety).
- Drowsiness
- Concentration problems
- Paresthesias (non-painful sensation in the area supplied by a cutaneous nerve with signs such as: Tingling, “formication”, furiness, tingling, itching, etc.).
- Speech disorders (aphasia)
- Visual disturbances (blurred vision, double vision).
- Confusion
- Transient hemiplegia (temporary hemiplegia).
- Psychosis or delirium
If blood glucose levels continue to fall (< 30-40 mg/dl/1.65-2.2 mmol/l), severe neurological disorders develop:
- Epilepsy (seizures).
- Unconsciousness
- Coma
Nonspecific signs. These represent accompanying symptoms that are not characteristic of hypoglycemia:
- Cephalgia (headache).
- Nausea (nausea)
- Vertigo (dizziness)
Caution. In slow-onset hypoglycemia, autonomic signs may be absent and neuroglycopenic signs may occur without warning. This then suddenly leads to severe central nervous system dysfunction (hypoglycemic shock; also known as hypoglycemic coma).
Symptoms of hypoglycemia as a function of serum glucose level
| Glucose serum level (mmol/l) | Symptoms |
| 3,8 | Increase in counterregulatory hormones (glucagon, epinephrine, growth hormone, cortisol). |
| 3,3 | Autonomous symptoms |
| 2,75 | Neuroglycopenic symptoms: Driving, flight of thought, talkativeness (logorrhea), irritability, visual disturbances, drowsiness, dizziness, word-finding disorders, coordination disorders in advanced stages: convulsions, limited ability to act, limited consciousness up to unconsciousness |
| 2,2 | Lethargy |
| 1,6 | Coma |
| 1,1 | Epilepsy |
| 0,5 | Permanent damage, death |
Hypoglycemia in the elderly
- During diabetic life, the perception of hypoglycemia decreases in type 1 diabetics. This demonstrates the importance of including hypoglycemia awareness training in patient education. The same applies to the type 2 diabetic.
- In older patients, autonomic and neuroglycopenic symptoms do not increase as markedly at the end of hypoglycemia as in patients around 50 years of age. Furthermore, the time between the perception of symptoms and a response is significantly prolonged.
