What Are the Causes of Irritability & Blood Sugar Levels?

Blood sugar levels and irritability are linked together in sometimes complex ways. Either low or high blood sugar can cause irritability, anger and aggression. Irritability and stress can affect blood-sugar levels, as can certain illnesses and other medical conditions.

Adrenal Gland, Cortisol and Irritability

• When the brain, specifically, the hypothalamus of the brain, detects stress, it signals the pituitary gland to release a hormone (CRH), which in turn triggers the adrenal gland to release the stress hormone cortisol. Cortisol prepares the body for the physical exertion required during stress by heightening sympathetic nervous system arousal. This arousal tends to increases irritability.

Cortisol Functions and Blood Sugar

• Cortisol increases heart rate; regulates blood pressure; slows the immune system’s inflammatory response; regulates metabolism of proteins, carbohydrates and fats; and maintains levels of glucose in the blood.

Blood Sugars and the Adrenal Gland

• When blood sugars are high, the pituitary gland and hypothalamus of the brain signal the adrenal gland to release cortisol in order to reduce blood sugar levels. Consequently, high blood sugar contributes to irritability by triggering the release of cortisol.

Hypoglycemia

• Hypoglycemia is a medical condition that results when blood sugar is low. One of the effects of hypoglycemia is irritability. Irritability likely reflects a state of heightened motivation and serves the purpose of alerting you to the need to eat in order to increase blood sugar levels.

Medical Conditions

• Certain medical conditions, including diseases of the adrenal gland such as Cushing’s disease, adrenal insufficiency syndrome, Addison’s disease and chemical poisoning, affect both blood-sugar levels and irritability.