Diabetes and Irrational Behavior, Mental Confusion

Diabetes and irrational behavior and mental confusion are dangerous consequences of blood sugar fluctuations. Get signs, causes, and treatment on HealthyPlace.

Two little-known but common effects of diabetes are irrational behavior and mental confusion. Diabetes impacts not only physical and mental health but behavioral health, too. The reasons for this are the hormone insulin and the levels of glucose, or sugar, in the bloodstream. Glucose powers the brain and is the force behind all of its functioning. In both type 1 and type 2 diabetes, the body can’t regulate its glucose levels, so glucose can soar too high or plummet too low. Diabetes and irrational behavior and mental confusion are among the dangerous consequences of blood sugar fluctuations.

Diabetes and Irrational Behavior, Mental Confusion: What They’re Like

In diabetes, irrational behavior happens because glucose levels that are too high (hyperglycemia) or, especially, too low (hypoglycemia) impede self-control. When people lack their normal level of self-control, they often:

  • are impulsive
  • disregard long-term consequences of their actions
  • easily give in to temptation
  • make poor decisions even when they’re aware of different choices

Irrational behavior in diabetes can reduce the quality of life if it happens often or affects major life areas like relationships and work. Mental confusion also has the potential to negatively affect someone’s life. Bouts of confusion, when they’re severe or long-lasting, can limit lifestyle and such things as freedom of movement and ability to work.

Signs of diabetes mental confusion include:

  • forgetfulness, including forgetting what you’re doing while you’re doing it
  • a sensation of brain fog
  • losing important objects
  • difficulty concentrating
  • confusion
  • long pauses during speech, as if you’ve lost your train of thought
  • feeling like you can’t think
  • disorientation
  • sudden agitation ("Diabetic Rage: Can Diabetes Cause Aggressive Behavior?")
  • difficulty doing ordinary tasks
  • incoherent speech

Diabetes and irrational behavior, as well as mental confusion, have specific causes related to blood sugar levels and insulin. Knowing their cause can help you understand what’s happening when you or a loved one experiences these behaviors and emotions, and it can help you manage them as well.

Causes of Diabetes and Irrational Behavior, Mental Confusion

When someone without diabetes eats carbohydrates, the carbs are digested and transformed into glucose, the sugar that gives the entire body and brain energy. Glucose leaves the digestive system and enters the bloodstream to be delivered to the body’s cells. Glucose can’t get into the cells on its own. That’s where insulin comes into the picture. An organ called the pancreas makes and releases insulin to unlock the cells and let glucose in.

In diabetes, this process goes awry. Type 1 diabetes is a disease in which the immune system attacks the pancreas so it can’t make insulin. In type 2 diabetes, the body can make insulin, but it either doesn’t make enough or it can’t use its insulin efficiently. Either way, glucose remains in the bloodstream rather than entering cells of the body for fuel; consequently, blood sugar levels climb too high and cause problems.

Diabetes treatment involves manually regulating insulin and blood sugar. This is difficult, and sometimes blood sugar levels become off center. When they’re too high (above 140 mg/dL), too low (below 70 mg/dL), or remain in the normal range but swing up and down, blood sugar levels aren’t where they need to be for the brain to operate correctly. Irrational behavior and mental confusion can result.

These factors contribute to the development of hyperglycemia, hypoglycemia, and unstable spikes and dips:

  • Taking too much diabetes medication, especially insulin
  • Eating too little
  • Waiting too long between snacks or meals
  • Too little exercise
  • Too much exercise
  • Alcohol consumption
  • Lack of sleep

Once you know the causes of the irrational behavior and mental confusion that can accompany diabetes, you can use your knowledge to prevent and treat these serious effects of hyperglycemia, hypoglycemia, and glucose fluctuations.

Treating Diabetes and Mental Confusion, Irrational Behavior

Just as it is for other effects of diabetes, prevention is the primary way to manage the behavioral effects of diabetes. Following the plan set by your doctor and, ideally, the diabetes care team is important. Regular blood sugar monitoring, proper nutrition, exercise, healthy weight maintenance, and stress management are crucial in controlling blood sugar levels. This, in turn, has a positive effect on the brain.

By being aware of the signs of mental confusion and irrational behaviors, you can catch a glucose problem before it gets out of hand. Further, by staying on top of your diabetes treatment and management, you can reduce the negative effects of diabetes on the brain and behavior.

article references

APA Reference
Peterson, T. (2022, January 3). Diabetes and Irrational Behavior, Mental Confusion, HealthyPlace. Retrieved on 2024, July 20 from

Last Updated: January 12, 2022

Medically reviewed by Harry Croft, MD

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