How to Take Blood Pressure Manually: A Step-by-Step Guide

Taking blood pressure manually with a sphygmomanometer and stethoscope is one of the most fundamental clinical skills in healthcare. Whether you are a student nurse on your first placement, a newly qualified GP, or a seasoned practitioner brushing up on technique, knowing how to measure blood pressure by hand gives you a reliable baseline that no battery or software can replicate. Below is a complete, step-by-step walkthrough of the auscultatory method, including what equipment you need, how to prepare your patient, and the common mistakes that throw readings off.

In this article

• What equipment do you need to take blood pressure manually?
• How should you prepare the patient?
• Step-by-step: how to take blood pressure manually
• What are Korotkoff sounds and why do they matter?
• Common mistakes that affect your reading
• Tips for accurate manual blood pressure readings
• When should you use manual over digital?
• Recommended sphygmomanometers for manual measurement
• Frequently asked questions

What equipment do you need to take blood pressure manually?

Manual blood pressure measurement requires two instruments working together: an aneroid sphygmomanometer (the cuff, gauge, inflation bulb and valve) and a stethoscope. That is the complete kit. There is no screen, no automated inflation, and no algorithm interpreting the result for you. You are listening for real-time changes in blood flow through the brachial artery and reading the pressure on a calibrated dial.

When choosing a sphygmomanometer, look for a device with a clearly marked gauge face, a smooth thumbscrew valve for controlled deflation, and an artery marker on the cuff for correct placement. Cuff size matters enormously: a cuff that is too small will overestimate blood pressure, and one that is too large will underestimate it. The bladder inside the cuff should cover roughly 80% of the circumference of the upper arm. Most adult cuffs fit arms between 22 cm and 32 cm, but you should always have access to a small adult and a large adult cuff as well.

For the stethoscope, a dual-head model with a diaphragm side is ideal. The diaphragm picks up higher-frequency sounds more clearly, which is what you need when listening for the sharp tapping of Korotkoff sounds. If you need guidance on choosing one, our guide to choosing the right stethoscope covers what to look for.

How should you prepare the patient?

Accurate blood pressure measurement starts well before the cuff goes on. Patient preparation is one of the most overlooked steps, yet it has one of the biggest effects on the reading you get.

Before you begin, make sure the patient has:

• Been seated and resting for at least five minutes
• Not smoked, consumed caffeine, or exercised within the past 30 minutes
• An empty bladder (a full bladder can raise systolic pressure by up to 10 mmHg)
• Removed any tight clothing from the upper arm

During the measurement:

• The patient should sit upright with their back supported and feet flat on the floor
• Legs should be uncrossed (crossing legs can raise systolic pressure by 2 to 8 mmHg)
• The arm should rest on a flat surface at heart level, palm facing upward
• Neither you nor the patient should talk during the reading

These are not minor details. Research published by the American Heart Association shows that an unsupported arm can inflate a reading by up to 10 mmHg, and talking during measurement can add 10 to 15 mmHg. In a clinical setting where a few millimetres of mercury determine whether a patient starts antihypertensive medication, that margin is the difference between a correct and incorrect diagnosis.

Step-by-step: how to take blood pressure manually

With your patient prepared and your equipment to hand, follow these steps:

Step 1: Apply the cuff

Wrap the deflated cuff snugly around the bare upper arm, positioning the lower edge about 2 to 3 cm above the antecubital fossa (the crease of the elbow). Align the artery marker on the cuff with the brachial artery, which runs along the inner side of the arm. The cuff should be tight enough that you can just slide one finger underneath it.

Step 2: Estimate the systolic pressure by palpation

Before using the stethoscope, palpate the radial pulse at the wrist on the same arm. Close the valve on the inflation bulb and inflate the cuff while feeling the pulse. Note the pressure on the gauge at which the pulse disappears. This is your estimated systolic pressure. Deflate the cuff completely and wait 15 to 30 seconds before proceeding.

This palpation step is not optional. It protects you against the auscultatory gap, a silent interval between Korotkoff phases II and III where sounds temporarily disappear. Without the palpation estimate, you might start listening below the true systolic pressure and mistake the return of sound after the gap for the systolic reading, underestimating it by 20 mmHg or more.

Step 3: Position the stethoscope

Place the diaphragm of the stethoscope directly over the brachial artery, just below the lower edge of the cuff. Hold it firmly but without pressing too hard: excessive pressure can compress the artery and distort the sounds. Do not tuck the stethoscope head under the cuff, as this creates artefact noise.

Step 4: Inflate and listen

Inflate the cuff to 20 to 30 mmHg above your palpated systolic estimate. At this point, arterial blood flow is completely occluded and you should hear silence through the stethoscope.

Step 5: Deflate slowly and record the systolic reading

Open the valve gently, releasing pressure at a steady rate of 2 to 3 mmHg per second. Listen carefully. The first clear, repetitive tapping sound you hear is Korotkoff phase I, and the pressure shown on the gauge at that moment is the systolic blood pressure. Note it.

Step 6: Continue deflating and record the diastolic reading

Keep deflating at the same steady rate. The tapping sounds will change character, becoming softer and eventually muffled (phase IV), and then they will disappear entirely (phase V). The pressure at the point where all sound disappears is the diastolic blood pressure. Note it.

Step 7: Deflate fully and record

Open the valve completely to release all remaining pressure. Remove the cuff. Record the reading as systolic over diastolic (for example, 124/78 mmHg), along with the arm used, the cuff size, and the patient's position. If the reading seems unusually high or low, wait two to three minutes and repeat on the same arm.

What are Korotkoff sounds and why do they matter?

Korotkoff sounds are the audible markers of blood flow returning through a compressed artery. First described by Russian surgeon Nikolai Korotkoff in 1905, they remain the gold standard reference for non-invasive blood pressure measurement. Understanding the five phases helps you take consistently accurate readings.

Phase	What you hear	Clinical meaning
Phase I	Clear, repetitive tapping (at least two consecutive beats)	Systolic blood pressure
Phase II	Softer tapping with a swishing or murmur quality	No direct clinical value; marks the auscultatory gap zone
Phase III	Sharper, louder tapping (similar to Phase I but crisper)	No direct clinical value
Phase IV	Abrupt muffling; sounds become soft and blowing	Used as diastolic in some populations (e.g. pregnancy, children)
Phase V	Complete silence (all sounds disappear)	Diastolic blood pressure

In most adults, Phase V (the disappearance of sound) is used for the diastolic reading. In certain clinical situations, such as pregnancy or aortic regurgitation, sounds may never fully disappear; in those cases, Phase IV (muffling) is recorded as the diastolic value, and the reading is documented as, for example, "130/80/60" to show both Phase IV and Phase V values.

Common mistakes that affect your reading

Even experienced clinicians can fall into habits that compromise accuracy. Here are the most common errors and how to avoid them:

1. Deflating too fast. Releasing pressure faster than 2 to 3 mmHg per second means you might miss the first Korotkoff sound or overshoot the last one. This underestimates systolic and overestimates diastolic. Practice valve control until the descent is steady and predictable.

2. Using the wrong cuff size. A cuff that is too narrow for the arm will give a falsely high reading (sometimes by 10 to 40 mmHg). A cuff that is too wide will read low. Measure the arm circumference and select the correct cuff before inflating.

3. Placing the arm below heart level. If the arm hangs at the patient's side rather than resting at heart level, hydrostatic pressure adds to the reading, potentially inflating it by 10 mmHg or more.

4. Skipping the palpation step. Without estimating systolic pressure by palpation first, you risk missing an auscultatory gap and recording a dangerously low systolic value.

5. Talking during the reading. Conversation raises both the patient's blood pressure and the ambient noise, making it harder to hear faint Korotkoff sounds. Keep the room quiet.

6. Rounding to the nearest 10. Blood pressure should be recorded to the nearest 2 mmHg. "Terminal digit preference" (always writing readings ending in 0 or 5) is a well-documented source of measurement bias in clinical practice.

7. Measuring over clothing. A sleeve bunched above the cuff compresses the arm and distorts the reading. Always apply the cuff to bare skin.

Tips for accurate manual blood pressure readings

Calibrate your sphygmomanometer regularly. Aneroid gauges should be checked against a reference manometer at least every six months, or whenever dropped. A gauge that reads 4 mmHg high across the range means every patient you measure is getting a reading 4 mmHg too high.

Take at least two readings. NICE guidelines recommend taking two consecutive readings at least one minute apart, with the lower of the two used for clinical decisions. If the first two readings differ by more than 5 mmHg, take a third and average the last two.

Measure both arms on the first visit. A consistent difference of more than 15 mmHg between arms can indicate peripheral vascular disease. After the initial check, use the arm with the higher reading for future measurements.

Let the cuff fully deflate between readings. Venous congestion from a partially inflated cuff distorts subsequent readings. Wait at least one to two minutes with the cuff fully deflated before repeating.

Position yourself at eye level with the gauge. Parallax error occurs when you read the dial from an angle. The gauge should be at your eye level, no more than one metre away.

When should you use manual over digital?

Digital monitors are convenient and reduce observer bias, but manual measurement remains essential in several clinical situations:

• Irregular heart rhythms such as atrial fibrillation, where oscillometric algorithms may struggle to detect the true systolic and diastolic pressures
• Very low blood pressure, where weak Korotkoff sounds are still audible to a trained ear but may fall below a digital monitor's detection threshold
• Pregnancy, where Phase IV rather than Phase V may be needed for the diastolic reading
• Clinical skills assessments and OSCEs, where competency in manual technique is examined directly
• Validating a digital monitor's accuracy against a manual reference reading

For a detailed comparison of both methods, see our guide: Manual vs Digital Blood Pressure Monitors: Which Is More Accurate?

Recommended sphygmomanometers for manual measurement

The right sphygmomanometer makes accurate measurement easier. Here are four options from our range, covering everything from student-friendly entry-level devices to professional-grade instruments built for daily clinical use.

Need a complete rundown of every sphygmomanometer we stock? See our full guide: Best Sphygmomanometers for Nurses and Healthcare Professionals (UK).

Frequently asked questions

What is a normal blood pressure reading?

A normal reading for most adults is below 120/80 mmHg. The NHS classifies readings between 120/80 and 140/90 as slightly raised (pre-hypertension), and anything consistently at or above 140/90 as high blood pressure. Readings below 90/60 are generally considered low. These thresholds apply to clinic-based measurements; home and ambulatory thresholds are slightly lower.

How fast should I deflate the cuff?

Deflate at 2 to 3 mmHg per second (roughly one small graduation on the gauge per heartbeat for a patient with a resting heart rate of around 70 bpm). Faster deflation means you are likely to miss the first or last Korotkoff sound and record an inaccurate reading.

Why do I sometimes hear nothing when I start deflating?

If you hear no sounds at all as you deflate, either you did not inflate high enough above the true systolic pressure, or the stethoscope is not positioned correctly over the brachial artery. Deflate fully, reposition the stethoscope, and re-palpate to get a better systolic estimate before trying again.

Can I use a manual sphygmomanometer on myself?

It is possible but difficult. You need to inflate the cuff, operate the valve, hold the stethoscope, and read the gauge with one hand, which compromises technique. For self-monitoring at home, a validated automatic blood pressure monitor is more practical and more accurate. Our guide to the best blood pressure monitors for GP surgeries includes digital options suitable for both clinic and home use.

How often should I calibrate my aneroid sphygmomanometer?

At least every six months, or sooner if the device has been dropped. Check that the needle rests at zero when no pressure is applied. For a full accuracy check, compare your gauge against a calibrated reference manometer. Many manufacturers and medical equipment suppliers offer calibration services.

What is the auscultatory gap and how do I avoid missing it?

The auscultatory gap is a silent interval that can occur between Korotkoff phases II and III, where sounds temporarily disappear before returning. It is more common in elderly patients and those with hypertension. The only reliable way to avoid being caught out is to perform the palpation step (Step 2 above) before auscultation, so you know roughly where systolic pressure falls and can inflate well above it.

Related reading

• Best Sphygmomanometers for Nurses and Healthcare Professionals (UK)
• Best Blood Pressure Monitors for GP Surgeries and Clinics in 2026
• Manual vs Digital Blood Pressure Monitors: Which Is More Accurate?
• Top 6 Must-Have Diagnostic Tools for GP Surgeries in the UK