What is hyperosmolar hyperglycemic state?
Hyperosmolar hyperglycemic state (HHS) is a life-threatening complication of diabetes — mainly Type 2 diabetes. HHS happens when your blood glucose (sugar) levels are too high for a long period, leading to severe dehydration and confusion.
HHS requires immediate medical treatment. Without treatment, it can be fatal.
What’s the difference between DKA and HHS?
Diabetes-related ketoacidosis (DKA) and hyperosmolar hyperglycemic state (HHS) are both life-threatening diabetes complications related to high blood sugar (hyperglycemia), but they’re different conditions.
DKA happens when your body doesn’t have enough insulin. Your body needs insulin to turn glucose, your body’s go-to source of fuel, into energy. If there’s no insulin or not enough insulin, your body starts breaking down fat for energy instead. As your body breaks down fat, it releases ketones into your bloodstream. Ketones cause your blood to become acidic, which is life-threatening.
HHS happens when very high blood sugar leads to severe dehydration and highly concentrated blood (high osmolality), which are life-threatening. HHS also involves a lack of insulin, but the person usually still produces enough insulin to prevent the production of ketones. In addition, there’s usually an underlying condition, such as an infection, that’s also contributing to the high blood sugar.
The main difference between DKA and HHS is that DKA involves ketones and blood acidity; HHS doesn’t. The two complications have similar symptoms, including intense thirst, frequent urination and mental status changes.
Differences between DKA and HHS include:
| Markers | DKA | HHS |
|---|---|---|
| People affected. | Most commonly affects people with Type 1 diabetes. | Most commonly affects people with Type 2 diabetes. |
| Time to develop. | Develops quickly — often within 24 hours. | Develops more slowly — usually within days to weeks. |
| Blood sugar level. | Usually above 250 mg/dL. | Higher than 600 mg/dL. |
| Urine or blood ketones. | Present. | Trace or none. |
| Blood pH level. | 7.3 or lower. | Higher than 7.3. |
| Mortality rate. | About 1% to 8%. | About 10% to 20%. |
| Markers | ||
| People affected. | ||
| DKA | ||
| Most commonly affects people with Type 1 diabetes. | ||
| HHS | ||
| Most commonly affects people with Type 2 diabetes. | ||
| Time to develop. | ||
| DKA | ||
| Develops quickly — often within 24 hours. | ||
| HHS | ||
| Develops more slowly — usually within days to weeks. | ||
| Blood sugar level. | ||
| DKA | ||
| Usually above 250 mg/dL. | ||
| HHS | ||
| Higher than 600 mg/dL. | ||
| Urine or blood ketones. | ||
| DKA | ||
| Present. | ||
| HHS | ||
| Trace or none. | ||
| Blood pH level. | ||
| DKA | ||
| 7.3 or lower. | ||
| HHS | ||
| Higher than 7.3. | ||
| Mortality rate. | ||
| DKA | ||
| About 1% to 8%. | ||
| HHS | ||
| About 10% to 20%. |
How common is HHS?
It’s difficult for researchers to determine how common HHS is, but they think it’s relatively uncommon compared to other diabetes-related complications. Some studies show that about 1% of all hospital admissions for diabetes are due to HHS.
