Another Bodily Response
Besides a drop in blood-glucose concentrations, another reason people can become hangry is the glucose counter-regulatory response. Let me explain.
When blood-glucose levels drop to a certain threshold, your brain sends instructions to several organs in your body to synthesise and release hormones that increase the amount of glucose in your bloodstream.
The four main glucose counter-regulatory hormones are: growth hormone from the pituitary gland situated deep in the brain; glucagon from the pancreas; and adrenaline, which is sometimes called epinephrine, and cortisol, which are both from the adrenal glands. These latter two glucose counter-regulatory hormones are stress hormones that are released into your bloodstream in all sorts of stressful situations, not just when you experience the physical stress of low blood-glucose levels.
In fact, adrenaline is one of the major hormones released into your bloodstream with the “fight or flight” response to a sudden scare, such as when you see, hear or even think something that threatens your safety. Just as you might easily shout out in anger at someone during the “fight or flight” response, the flood of adrenaline you get during the glucose counter-regulatory response can promote a similar response.