An Overview of Brittle Diabetes

Hard to Control Type 1 Diabetes

In This Article

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Brittle diabetes, also called labile diabetes, is a term used to describe hard-to-control type 1 diabetes. People with brittle diabetes frequently experience large swings in blood sugar (glucose) levels which can quickly move from too high (hyperglycemia) to too low (hypoglycemia) or vice versa. This type of diabetes is very rare.

According to the National Institute of Health (NIH), only a small proportion of people with type 1 diabetes experience the frequent blood glucose swings described as “brittle.” It affects approximately 3/1000 insulin-dependent people with diabetes, mainly young women, with overweight women more likely to be affected. Most people with brittle diabetes tend to be between the ages of 15 and 30.

Causes and Risks 

The most significant risk factor is having type 1 diabetes. Others risks include:

  • being overweight
  • being a woman
  • age (most commonly seen between the ages of 15-to-30)
  • depression and stress
  • eating disorders
  • gastrointestinal absorption problems, including delayed stomach emptying (gastroparesis), Celiac disease
  • drug interactions
  • problems with insulin absorption
  • hormonal malfunction
  • hypothyroidism
  • adrenal insufficiency


The blood sugar levels of people with stable diabetes may fluctuate occasionally. However, these fluctuations are not frequent and—unlike brittle diabetes—do not impact the ability to carry out regular activities of daily living. People with brittle diabetes may experiece:

  • frequent blood sugar shifts, from high to low or vice versa that happen rapidly

Symtoms of high blood sugar (hyperglycemia) include:

  • fatigue
  • blurry vision
  • excessive thirst
  • increased hunger
  • increased urination
  • fruity breath
  • nausea and vomiting

Symptoms of low blood sugar include:

  • confusion
  • lack of energy, fatigue, tiredness
  • dizziness
  • feeling shaky or anxious
  • increased heartbeat
  • sweating
  • headache


Diagnosis of brittle diabetes is pretty rare and tricky. Typically, if diagnosed, it is usually coupled with pyschological problems, such as stress and depression. In some cases, psychological problems lead to neglect self-care for diabetes. For example, people with brittle diabetes may stop maintaining a healthy diet or management of their blood sugar. As blood sugar control wanes, metabolic imbalances further complicate and often worsen the underlying psychological problems, causing a repetitive cycle of brittle diabetes.

One small study documented that people with brittle diabetes have a greater hormonal response to stress than those whose diabetes is not brittle. This psychological-hormonal connection may influence the development of brittle diabetes.


Identifying and correcting the underlying issues, whether physiologic or psychological, is essential to treating brittle diabetes. Blood tests can help to determine the cause of glucose instability. If blood glucose responds normally to diabetes drugs in a controlled environment (such as in a hospitalized patient), then one should look for environmental, psychological or behavioral causes.

While there may be a physiological explanation for brittle diabetes, that's only one of the potential behavioral/environmental explanations, and diagnosing a psychological cause of brittle diabetes can often be a lengthy and challenging process.

If the cause is determined to be psychological, treatment may involve exploring and trying to lessen the stress of the person's situation. It is helpful to consult a psychology professional in evaluating and treating these patients. Psychotherapy has proven to be effective in treating brittle diabetes.

Patients with brittle diabetes may sometimes need to be transferred to a different diabetes care team or center for a fresh start managing their diabetes. Switching to a specialty diabetes center can sometimes help to break the cycle of brittle diabetes.

Treating brittle diabetes may require a prolonged hospital stay of a few weeks with intensive monitoring of food, glucose, and insulin.

The More Information You Have the Better

The more information you have regarding your blood sugars the better you can manage your medications and reduce the frequency of blood glucose excursions. For many people with type 1 diabetes, this may mean wearing a continuous glucose monitor and using an insulin pump. 

Continuous glucose monitors can help you to identify when your blood sugar is dropping or spiking so that you can take necessary steps to get your sugar under control. 

Insulin pumps can make insulin dosing much more precise. They aim to mimic how a normal functioning pancreas would act: delivering a small amount of insulin all day long to cover the bodies' need for insulin and delivering larger doses of insulin when a person ingests carbohydrates for meals. These pumps don't do all the work for you, you must still be able to carbohydrate count and monitor your blood sugar, but when used properly they can enable us to manage insulin needs better than insulin injections. 

Another option, if you are eligible, maybe islet cell transplantation. Islet cell transplantation, specifically allo-transplantation, is currently being used on a very select population of people with type 1 diabetes who have an extremely difficult time managing their blood sugars or have a severe case of hypoglycemia unawareness. Transplants are only performed in clinical research hospitals that have had approval by the FDA.


The person with brittle diabetes is frequently hospitalized, misses work, and often has to contend with psychological problems. All of these factors place additional emotional and financial stress on family members. It's important that you reach out to your medical team for support for yourself and your family members.

A Word from Verywell

Brittle diabetes or "labile diabetes" is a very rare condition, characterized by extreme swings in blood sugar. It most commonly occurs, in young oveweight women with type 1 diabetes. Oftentimes, people with brittle diabetes also have another underlying condition, such as depression, extreme stress, hormonal dysfunction, or hypothyroidism, to name a few. Knowing the signs and symptoms of both high and low blood sugar, as well as getting psychological support can help to lessen the burden for yourself and your family. Additionally, the more information you have regarding your blood sugar control, the better.

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Article Sources

  • McCulloch, David K. "The Patient with Brittle Diabetes Mellitus." 2007. UpToDate. 18 Sep 2007
  • National Institute of Diabetes and Digestive and Kidney Disease. Pancreatic Islet Transplantation.
  • National Institute of Health. Brittle diabetes. 
  • Vantyghem MC, Press M. Management strategies for britlle diabetes. Ann Endocrinol (Paris). 2006 Sep;67(4):287-96.