HYPOTENSION
Cardiovascular Disorders | Adult Health Nursing-I
Complete Nursing Notes • Clinical Cases • NORCET MCQ Test
- Define hypotension and recognize its clinical significance.
- Understand causes, types, pathophysiology and clinical manifestations.
- Explain diagnostic assessment and medical management.
- Identify shock and other emergency warning signs.
- Describe nursing interventions and patient education.
1. Definition of hypotension
Hypotension is blood pressure that is abnormally low for an individual's clinical circumstances and may impair blood flow to vital organs.
A blood pressure below approximately 90/60 mmHg is commonly described as low in adults. However, some healthy people naturally have lower readings without symptoms. A sudden fall from the person's usual BP or low BP with signs of poor organ perfusion is particularly concerning.
2. Types of hypotension
A. Orthostatic (postural) hypotension
A fall in BP after standing from a sitting or lying position. A commonly used definition is a sustained decrease in systolic BP of at least 20 mmHg or diastolic BP of at least 10 mmHg within three minutes of standing.
- Symptoms: dizziness, light-headedness, blurred vision, weakness or syncope.
- Causes: dehydration, blood loss, autonomic dysfunction and certain medicines.
- Nursing care: assist with position changes, assess fall risk and measure lying and standing BP when safe and indicated.
B. Postprandial hypotension
A decrease in BP after eating, particularly in older adults and people with autonomic dysfunction. Symptoms may include dizziness, weakness or faintness after meals.
C. Acute hypotension
A sudden fall in BP may result from bleeding, severe dehydration, anaphylaxis, sepsis, cardiac dysfunction or other acute conditions. It may be life-threatening when organ perfusion is compromised.
D. Chronic or persistent hypotension
Low BP that persists over time. It may be normal for some individuals, but symptoms or a change from baseline requires assessment for an underlying cause.
3. Causes and risk factors
- Dehydration: vomiting, diarrhea, fever, sweating or inadequate fluid intake.
- Blood loss: trauma, gastrointestinal bleeding or postpartum hemorrhage.
- Cardiac causes: myocardial infarction, severe arrhythmias, heart failure or valve disease.
- Severe infection: sepsis can cause vasodilation and capillary leakage.
- Severe allergic reaction: anaphylaxis can produce vasodilation, airway swelling and shock.
- Endocrine problems: adrenal insufficiency and selected thyroid disorders.
- Medicines: antihypertensives, diuretics, nitrates and some psychiatric or other medicines.
- Autonomic dysfunction: impaired regulation of blood pressure when changing position.
- Pregnancy: vascular changes may lower BP, but significant symptoms or bleeding require prompt evaluation.
4. Pathophysiology
Blood pressure depends largely on cardiac output and systemic vascular resistance. Hypotension may develop when circulating blood volume falls, cardiac pumping is impaired or blood vessels dilate excessively.
Simplified educational diagram: the mechanism depends on the underlying cause.
5. Clinical manifestations
- Dizziness or light-headedness.
- Fainting or near-syncope.
- Weakness, fatigue or blurred vision.
- Nausea in some patients.
- Cool, pale or clammy skin, particularly in some shock states.
- Tachycardia may occur as a compensatory response, although it is not present in every cause.
- Confusion, reduced consciousness or reduced urine output may indicate poor organ perfusion.
6. Assessment and diagnosis
History
- Onset, duration and pattern of symptoms.
- Fluid intake, vomiting, diarrhea, fever and recent blood loss.
- Current medicines and recent dose changes.
- Cardiac history, diabetes, endocrine disease and recent infection.
- Relationship of symptoms to standing or meals.
Physical assessment
- Measure BP correctly and repeat to assess the trend.
- Assess pulse, respiratory rate, oxygen saturation, temperature and mental status.
- Assess skin temperature, capillary refill and peripheral perfusion.
- Measure urine output when clinically indicated.
- Check orthostatic BP only when safe; do not make an unstable patient stand for testing.
Investigations according to suspected cause
| Investigation | Purpose |
|---|---|
| CBC | Assess anemia or possible infection. |
| Electrolytes, urea and creatinine | Assess fluid/electrolyte abnormalities and kidney function. |
| ECG | Assess rhythm abnormalities or possible cardiac ischemia. |
| Blood glucose | Identify hypoglycemia or hyperglycemia when relevant. |
| Lactate and blood cultures | May be indicated when shock or sepsis is suspected. |
| Troponin | When myocardial injury is suspected. |
| Echocardiography or imaging | When cardiac dysfunction, internal bleeding or another specific cause is suspected. |
7. Medical management
Treatment depends on the cause and the patient's clinical condition. The priority is to support organ perfusion while identifying and treating the underlying problem.
- Fluid replacement: Oral fluids may be appropriate in selected stable patients. IV isotonic fluids may be needed for hypovolemia or shock, with careful reassessment and consideration of heart or kidney failure.
- Control bleeding: Identify the source and arrange urgent hemorrhage control and blood products when indicated.
- Treat infection: Suspected septic shock requires urgent protocol-based care, antimicrobials and source control as indicated.
- Treat anaphylaxis: Intramuscular epinephrine is first-line treatment for anaphylaxis, alongside emergency airway and circulatory support.
- Cardiac management: Treat arrhythmias, acute myocardial infarction or other cardiac causes according to clinical findings.
- Vasopressors: May be required in monitored critical-care settings when hypotension persists despite appropriate initial management. Norepinephrine is commonly the first-line vasopressor for septic shock in adults.
- Review medicines: A clinician may adjust medicines that contribute to hypotension.
8. Nursing management
Immediate priorities
- Assess airway, breathing and circulation.
- Call for urgent assistance if the patient is unstable or has signs of shock.
- Position the patient safely, generally supine if tolerated, and protect against falls. Do not force a position that worsens breathing.
- Monitor BP, pulse, respiratory rate, oxygen saturation and consciousness frequently according to acuity.
- Administer oxygen when indicated by hypoxemia or emergency protocol.
- Establish IV access and assist with prescribed fluids, blood products and medications.
- Monitor urine output and other indicators of organ perfusion when indicated.
- Identify and report possible bleeding, infection, arrhythmias or medication effects.
- Document findings, interventions and the patient's response.
Ongoing nursing care
- Assist with slow position changes when postural hypotension is suspected.
- Implement fall-prevention measures and assist with ambulation.
- Review medicines with the clinical team when hypotension follows a dose or medication change.
- Monitor hydration and intake/output when clinically appropriate.
- Teach the patient to report recurrent dizziness, fainting or new symptoms.
- Encourage an individualized fluid intake plan rather than universal fluid loading.
9. Patient education
- Rise slowly from lying to sitting and then standing.
- Sit or lie down immediately if feeling faint to reduce the risk of falling.
- Follow the clinician's fluid and salt recommendations; extra salt is not appropriate for everyone.
- Do not stop or change prescribed medicines without discussing them with the clinician.
- Keep a record of BP and symptoms if advised.
- Seek urgent care for fainting with chest pain, severe breathlessness, major bleeding, confusion or signs of shock.
10. Hypotension versus hypertension
| Feature | Hypotension | Hypertension |
|---|---|---|
| Blood pressure | Abnormally low for the clinical context | Persistently elevated above diagnostic thresholds |
| Common concern | Inadequate organ perfusion | Long-term cardiovascular and organ damage |
| Possible symptoms | Dizziness, fainting, weakness | Often none |
| Possible causes | Fluid loss, bleeding, cardiac dysfunction, vasodilation | Primary multifactorial causes or secondary conditions |
| Management | Treat cause and support perfusion | Lifestyle changes and prescribed BP-lowering therapy |
11. NORCET high-yield revision
- Adult BP below approximately 90/60 mmHg is commonly called low, but symptoms and baseline matter.
- Orthostatic hypotension: a sustained fall of at least 20 mmHg systolic or 10 mmHg diastolic within three minutes of standing.
- Major blood loss can cause hypovolemic shock.
- Sepsis may cause vasodilation and distributive shock.
- Cardiac pump failure may cause cardiogenic shock.
- Assess ABCs and perfusion in an unstable patient.
- Do not stand an unstable patient to obtain orthostatic readings.
- IV fluids should be individualized and reassessed.
- IM epinephrine is first-line treatment for anaphylaxis.
- Persistent hypotension with confusion, oliguria or cool clammy skin can indicate poor perfusion.
12. Hypotension MCQ Practice Test
25 Questions | 30 Minutes
Choose one answer per question. The test shows one question at a time. Use Previous, Next and Submit Test.
Educational disclaimer: This material is for nursing education and exam preparation. Patient assessment and treatment should follow current clinical guidelines and local protocols.