Recognising Hyperosmolar Hyperglycaemic State for Student Nurses
Learn how to recognise hyperosmolar hyperglycaemic state, identify dehydration and neurological deterioration, and understand why HHS requires urgent clinical assessment.
What is HHS?
Hyperosmolar hyperglycaemic state, or HHS, is a serious complication of diabetes in which blood glucose becomes very high and severe dehydration develops. It often evolves more gradually than diabetic ketoacidosis.
Very high blood glucose
Marked hyperglycaemia forms part of the HHS picture but must be interpreted alongside symptoms and clinical findings.
Severe dehydration
Increased urination and reduced intake can lead to substantial fluid depletion.
Consciousness may change
Confusion, drowsiness or other neurological change can occur as severity increases.
What might you notice?
| Finding | Possible presentation | Why it matters |
|---|---|---|
| Marked thirst | The patient drinks frequently or reports persistent thirst. | This may reflect substantial fluid loss. |
| Frequent urination | Passing large amounts of urine or urinating more often. | Osmotic diuresis can lead to progressive dehydration. |
| Dryness | Dry mouth, dry mucous membranes or reduced skin moisture. | These findings may contribute to assessment of dehydration. |
| Tachycardia | Pulse becomes faster than previous observations. | This may accompany reduced circulating volume. |
| Falling blood pressure | Blood pressure drops as illness progresses. | This may indicate worsening circulatory compromise. |
| Neurological change | Confusion, drowsiness, weakness or reduced responsiveness. | Neurological deterioration is an important marker of severity. |
HHS can develop over several days
The patient may initially report thirst and frequent urination before gradually becoming increasingly dehydrated, weak and confused.
Build the clinical picture systematically
Check glucose
Measure blood glucose when indicated and within your competence and local policy.
Assess hydration
Ask about thirst, fluid intake and urinary frequency and look for signs of dehydration.
Review circulation
Assess pulse, blood pressure, peripheral perfusion and other circulatory observations.
Assess consciousness
Look for confusion, drowsiness, altered behaviour or reduced responsiveness.
Review the trend
Compare current glucose, observations and clinical condition with earlier findings.
Escalate promptly
Significant hyperglycaemia with dehydration or neurological deterioration requires urgent clinical review.
Assess deterioration using ABCDE
Airway
Confirm that the airway is patent, particularly if consciousness is reduced.
Breathing
Assess respiratory rate, oxygen saturation, depth and pattern of breathing.
Circulation
Assess pulse, blood pressure, perfusion and evidence of marked fluid depletion.
Disability
Check blood glucose and assess consciousness, confusion and other neurological changes.
Exposure
Consider temperature, infection and other possible triggers or sources of deterioration.
Emergency escalation
Obtain registered and medical support according to local diabetic emergency procedures.
Who may be at risk?
HHS is often associated with type 2 diabetes and may occur when another illness or change in treatment disrupts glucose control.
Acute illness
Infection and other physiological stressors can contribute to significant hyperglycaemia.
Difficulty maintaining fluids
Poor fluid intake can accelerate dehydration when urinary losses are already high.
Medication changes
Missed diabetes medication or changes in the clinical situation may contribute to deteriorating glucose control.
Recognise that the patterns differ
| Feature | HHS pattern | DKA pattern |
|---|---|---|
| Onset | Often develops more gradually over days. | Can develop more rapidly. |
| Hyperglycaemia | Usually marked. | Usually present but glucose level alone does not define DKA. |
| Dehydration | Can be profound. | Also common. |
| Ketones | Usually not the dominant feature. | Ketonaemia is central to the condition. |
| Neurological change | Can be prominent as severity increases. | May occur in severe deterioration. |
Both are emergencies
Students do not need to independently distinguish every biochemical feature. Recognise serious metabolic deterioration and obtain prompt clinical support.
Watch for progressive deterioration
Increasing thirst
The patient reports drinking much more than usual and passing urine frequently.
Dehydration develops
The patient becomes increasingly weak, dry and unable to maintain adequate oral intake.
Neurological deterioration
Glucose remains markedly elevated and the patient becomes confused and drowsy.
The gradual trend can hide severity
Because HHS may evolve over several days, each individual symptom can appear relatively non-specific until the full pattern is recognised.
Putting the findings together
Example
An older patient with type 2 diabetes has been unwell with an infection for several days.
They have become extremely thirsty and have been passing urine frequently, but their oral fluid intake has now fallen.
Their blood glucose is markedly elevated. Their pulse has increased, their blood pressure is lower than earlier and they appear very dry.
They are also becoming confused and increasingly drowsy.
The concern is the combined pattern of severe hyperglycaemia, progressive dehydration, circulatory change and neurological deterioration.
As a student nurse, recognise a possible serious diabetic emergency, continue an appropriate ABCDE assessment within your competence and obtain prompt registered and medical support.
HHS recognition errors to avoid
- Treating it as simply a high glucose reading. Look for dehydration and wider deterioration.
- Missing gradual deterioration. Review the trend over hours and days.
- Ignoring thirst and urinary frequency. They may represent major ongoing fluid loss.
- Failing to assess hydration. Severe dehydration is a key feature.
- Assuming confusion is unrelated. Neurological change may form part of the emergency.
- Waiting for profound hypotension. Escalate when the pattern becomes concerning.
- Trying to distinguish HHS from DKA without appropriate investigations. Recognise and escalate the emergency.
Describe the full pattern
Example escalation
“I'm concerned about Mrs Taylor. Her glucose is markedly elevated and she has been extremely thirsty and passing urine frequently. She now looks dehydrated, her pulse has increased, her blood pressure is lower and she is becoming confused and drowsy.”
This communicates the hyperglycaemia, dehydration, circulatory change and neurological deterioration.
Recognise → assess → communicate → escalate
Notice the metabolic pattern
Look for severe hyperglycaemia alongside marked thirst, frequent urination and dehydration.
Use ABCDE
Assess hydration, circulation, glucose, breathing and consciousness systematically.
Seek urgent review
Report the glucose trend, fluid-loss symptoms and neurological or circulatory deterioration promptly.
Build your diabetic-emergency recognition skills
Continue developing your ability to recognise metabolic deterioration, use ABCDE and communicate concerns clearly through the NurseNet Clinical Confidence pathway.
Explore Clinical Confidence →