A student nurse’s guide
Taking a blood pressure is one of the most common nursing skills you’ll perform — in labs, on placement, and throughout your career. While it may seem simple, accuracy and interpretation are critical, as BP readings can provide early clues to deterioration, chronic disease, or acute illness.
This guide will walk you through how to correctly take a blood pressure, how to understand the numbers, and what abnormal results might indicate.
What Is Blood Pressure?
Blood pressure measures the force of blood against arterial walls as the heart pumps.
It is recorded as two numbers:
- Systolic pressure – pressure during heart contraction
- Diastolic pressure – pressure during heart relaxation
Example: 120/80 mmHg
Equipment Needed
- Manual sphygmomanometer or automated BP machine
- Correctly sized cuff
- Stethoscope (for manual BP)
⚠️ Using the wrong cuff size is one of the most common causes of inaccurate readings.
How to Take a Blood Pressure (Manual Method)
1. Prepare the Patient
- Patient should be seated or lying comfortably
- Arm supported at heart level
- Feet flat on the floor, legs uncrossed
- Patient rested for at least 5 minutes
- Avoid talking during the reading
2. Apply the Cuff
- Wrap cuff snugly around the upper arm
- Place the cuff 2–3 cm above the antecubital fossa
- Align cuff marker over the brachial artery
3. Locate the Brachial Pulse
- Palpate the brachial artery
- Place your stethoscope diaphragm over it (do not place under cuff)
4. Inflate the Cuff
- Close the valve
- Inflate cuff to 20–30 mmHg above where the pulse disappears
5. Deflate and Listen
- Slowly deflate at 2–3 mmHg per second
- First sound (Korotkoff sound) = systolic BP
- Disappearance of sound = diastolic BP
6. Record the Result
Document:
- BP reading (e.g. 118/76 mmHg)
- Which arm
- Patient position
- Manual or automated
Understanding Blood Pressure Results
| Category | Systolic | Diastolic |
|---|---|---|
| Normal | <120 | <80 |
| Elevated | 120–129 | <80 |
| Hypertension | ≥130 | ≥80 |
| Hypotension | <90 | <60 |
(Ranges may vary slightly by guideline and clinical context)
What Abnormal Readings Might Mean
High Blood Pressure (Hypertension)
May be associated with:
- Chronic hypertension
- Stress or pain
- Kidney disease
- Cardiovascular disease
Risks: stroke, heart attack, kidney damage
Low Blood Pressure (Hypotension)
May be caused by:
- Dehydration
- Blood loss
- Sepsis
- Medication effects
Watch for: dizziness, syncope, confusion, shock
Concerning Situations
- Sudden BP changes
- Asymptomatic hypertension
- Hypotension with symptoms
Always escalate abnormal results according to hospital policy.
Tips for Student Nurses
✔ Always use the correct cuff size
✔ Compare readings with patient baseline
✔ Recheck abnormal results
✔ Document clearly and accurately
Blood pressure isn’t just a number — it’s a vital clue to what’s happening inside the body.