Hyperosmolar Hyperglycemic State (HHS)

Overview


Plain-Language Overview

Hyperosmolar Hyperglycemic State (HHS) is a serious condition that affects the body's ability to manage blood sugar levels, primarily involving the endocrine system and metabolic regulation. It occurs when blood sugar becomes extremely high, causing the blood to become very concentrated or hyperosmolar. This leads to severe dehydration as the body tries to get rid of excess sugar through increased urination. The condition mainly affects people with type 2 diabetes and can develop over days to weeks. It can cause symptoms like extreme thirst, confusion, and weakness due to the imbalance of fluids and electrolytes. Without treatment, it can lead to dangerous complications such as seizures or coma. The main health impact is the disruption of normal brain and organ function due to dehydration and high blood sugar.

Clinical Definition

Hyperosmolar Hyperglycemic State (HHS) is an acute metabolic complication of type 2 diabetes mellitus characterized by severe hyperglycemia, profound dehydration, and increased plasma osmolality without significant ketoacidosis. It results from a relative insulin deficiency combined with increased counterregulatory hormones, leading to impaired glucose utilization and osmotic diuresis. The hallmark is a plasma glucose level typically exceeding 600 mg/dL, with serum osmolality above 320 mOsm/kg. Unlike diabetic ketoacidosis, HHS usually lacks significant ketonemia or acidosis due to sufficient insulin to suppress lipolysis. The condition is precipitated by infections, medications, or other stressors that increase insulin resistance or reduce insulin secretion. HHS carries a high risk of morbidity and mortality due to severe dehydration, electrolyte imbalances, and potential neurologic complications such as seizures or coma.

Clinical Presentation


Diagnostic Workup


Pathophysiology


Treatments


Prevention


Outcome & Complications


Differential Diagnoses


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