Reviewed by: Qin Yang, M.D., Ph.D. 4/18.
Hyperglycemic Hyperosmolar Syndrome (HHS) and Diabetic Ketoacidosis (DKA) are two complications of diabetes. If both conditions are left untreated, they may result in mortality. We will look at both conditions in this article to understand the similarities and differences between them.
Hyperglycemic Hyperosmolar Syndrome (HHS):
Hyperglycemic Hyperosmolar Syndrome (HHS) is a complication of type 2 diabetes. It occurs when there are an extremely high blood glucose level and dehydration. The kidneys try to correct the high sugar levels in the blood by allowing it to be expelled through urination.
However, this causes the body to lose more water and leads to a condition where the blood has a high amount of glucose and salt, called hyperosmolarity. This condition is dangerous because it may cause the body to get water out from other organs.
HHS may occur in people who either don’t have their diabetes under control or who have yet not been diagnosed with diabetes.
The condition may arise from infections, such as pneumonia and urinary tract infections. Other illnesses such as a stroke or heart attack may also increase the chances of developing HHS. Medications may play a role in HSS if they decrease the effect of insulin or if they are increasing fluid loss.
Diabetic Ketoacidosis (DKA):
Diabetic Ketoacidosis (DKA) is also a life-threatening complication of diabetes. It can occur in both type 1 and type 2 patients, but it is more common, and often the first sign for someone with type 1 diabetes.
According to a 2002 study, DKA was the initial manifestation of diabetes in 20% of adult patients and 30–40% of children with type 1 diabetes.
DKA occurs when the body starts breaking down fat in the body. The liver converts fat into energy, called ketones. This causes the blood to become acidic, called ketoacidosis.
Some of the common causes of DKA are when glucose can no longer be used as a fuel source by cells. It also occurs when the liver makes a large amount of blood sugar. And, when fat is broken down too quickly for the body to keep up.
The factors for DKA in patients who are already living with established diabetes include illnesses, infections, poor compliance with therapy, and psychological stress.
Even though there are certain differences in HHS and DKA, both of them have the same underlying mechanism.
HHS and DKA have been the most common life-threatening complications often faced by patients living with diabetes.
According to a 2002 study, while the mortality rate for DKA could be up to 2-5%, HHS could have a mortality rate as high as 15%. The mortality is usually as a result of the underlying causes of the conditions.
However, there could be some factors that could affect the outcome of the condition, including more effective treatment, as well as early identification and treatment of underlying causes.
Differences Between HHS And DKA:
- DKA is often found associated with patients with type 1 diabetes, and so, it affects people of younger age who either have undiagnosed or insulin-treated diabetes. However, HHS is common among the middle-aged or the elderly.
- In addition to age, type of diabetes, other two major distinguishable factors are:
DKA, glucose often< 800mg/dL, while HHS often > 1,000mg/dL
DKA, ketones are quite high, HHS, ketones negative or mildly positive
Symptoms of HHS:
- Increased thirst
- Increased urination
- Weight loss
Symptoms of DKA:
- Decreased alertness
- Deep, rapid breathing
- The frequent urination
- Feeling consistently thirsty
- Fruity-smelling breath
- A headache
- Nausea and vomiting
Treatment of HHS and DKA:
On a general note, the treatment of HHS and DKA requires frequent monitoring of patients, correction of hyperglycemia and hypovolemia, electrolyte replacement, and careful observation of the causes. In addition to treatment in the hospital, patients and caregivers should drink fluid, and give insulin injection (especially for patients on an insulin pump). You can learn more about DKA here. Some of the therapy options are below:
- Patients living with HHS and DKA have a drastic reduction in water. Therefore, fluid therapy is usually one of the treatments given
- Insulin therapy is a cornerstone in the management of HHS and DKA.
- Insulin therapy often leads to the reduction in the level of blood electrolytes, therefore, there is need to replenish them either through oral rehydration or through IV rehydration.
Qin Yang, M.D., Ph.D., is an Assistant Professor of Medicine, Physiology and Biophysics at the Center for Diabetes Research in the Department of Medicine, Division of Endocrinology, at the UC Irvine School of Medicine. He specializes in Endocrinology & Metabolism and Internal Medicine.
- “Diabetic hyperglycemic hyperosmolar syndrome,” 2016, February, 3. Retrieved from: https://medlineplus.gov/ency/article/000304.htm
- “Diabetic ketoacidosis,” 2018, January 16. Retrieved from: https://medlineplus.gov/ency/article/000320.htm
- Basu A, Close CF, Jenkins D, Krentz AJ, Nattrass M, Wright AD: “Persisting mortality in diabetic ketoacidosis.” Diabet Med 10:282–289, 1992
- Wiley Online Library. “Persisting Mortality in Diabetic Ketoacidosis.” Accessed April 25, 2018. http://onlinelibrary.wiley.com/doi/10.1111/j.1464-5491.1993.tb00060.x/full
- Arch Intern Med. 1997 Mar 24;157(6):669-75. “Hyperglycemic crises in urban blacks.” Accessed April 25, 2018. https://www.ncbi.nlm.nih.gov/pubmed/9080921?access_num=9080921&link_type=MED&dopt=Abstract
- Diabetes Spectrum 2002 Jan; 15(1): 28-36. “Diabetic Ketoacidosis and Hyperglycemic Hyperosmolar Syndrome.” Accessed April 25, 2018. http://spectrum.diabetesjournals.org/content/15/1/28