Does a Nerve Conduction Study Hurt, and How Long Does It Take?

Written by Jim Lewis R. NCS.T, CNCT

Updated September 2026 ·8 min read

Yes, some of it is uncomfortable. Most of it is not painful in the way people expect, it is over within about an hour, and there is nothing lasting afterwards.

What follows is an honest account of each part, because knowing which bit is coming is most of what makes it tolerable.

The two parts feel completely different

An electrodiagnostic appointment is two tests. The nerve conduction study uses surface electrodes and small electrical pulses; no needles are involved. The needle electromyogram uses a fine needle electrode placed into selected muscles. People often dread the wrong one.

What the electrical pulses feel like

A brief tap, a snap, or a jolt that makes the muscle twitch. Each pulse lasts a fraction of a second, and there are many of them. Most people describe it as startling rather than painful — the involuntary twitch is more unsettling than the sensation itself.

Intensity is not uniform across the study, and that is by design. Sensory nerves need less current than motor nerves. As Jim Lewis R. NCS.T, CNCT puts it, it is “less uncomfortable for the patient to do sensories, less intensity” — and a skilled operator can cover a great deal of the brachial plexus with sensory studies alone.

Deeper nerves and nerves under more tissue need more current, so a study of the leg is usually less comfortable than a study of the hand.

The parts that are genuinely less pleasant

Two additional techniques are worth knowing about, because both are more uncomfortable than the standard study and neither is always necessary.

F waves assess the long pathway, up the nerve and back, and require a stronger stimulus. They are essential in some conditions — Lewis is emphatic that in suspected Guillain-Barré syndrome “you must do F waves.” In routine carpal tunnel work his verdict is more pointed, and worth quoting in full because it tells you how a good examiner thinks: “it doesn't hurt to do it. It hurts the patient, but it doesn't hurt to do it — but it doesn't give us a lot of information.”

The blink reflex examines the facial and trigeminal nerves. Lewis calls it plainly “an uncomfortable test” and notes it is performed far less often than it once was — genuinely valuable in early Guillain-Barré, rarely needed when Bell's palsy is already obvious.

If either is proposed, it is entirely reasonable to ask what it will add.

Does the needle part hurt?

Less than most people expect. The needle electrode is very fine and nothing is injected — it records rather than delivers. There is a small sharp sensation on insertion, then a deep ache while the needle is repositioned.

That repositioning is the part worth understanding, because it is what makes the study valid. The muscle is sampled at several depths and along more than one trajectory rather than at a single point. As Lewis describes it, the needle is moved through the muscle, stopping several times, then withdrawn and passed along a different track — “we want to look at a good sampling of that muscle, not just one place.”

You will be asked to relax completely, then to contract gently. The contraction is often the most uncomfortable moment, and it is brief.

Afterwards the muscles that were examined may feel bruised for a day or two, much like the day after unaccustomed exercise. Minor bruising at needle sites is common and settles.

How long does a nerve conduction study take?

Plan on about an hour for an upper limb study with needle EMG. Lower limb studies, and any study covering both sides, take longer — up to about ninety minutes.

If your appointment is much shorter than that, it is worth knowing what has been traded. Lewis is direct about the commercial pressure on the hour: “I wish it was still an hour to an hour and a half, because I gotta tell you, I see people doing these in twenty minutes all the time. Give yourself enough time.” He acknowledges why it happens — “the folks in the corner office want you to do more, not less” — and his answer is to bring in a trained technologist for the first forty-five minutes, not to shorten the study.

A twenty-minute study is a smaller study, with fewer nerves examined and more room for something to be missed.

Why they will want you warm, and why it matters to you

You may be given a warming blanket or asked to soak your hands. This is not a comfort measure, though it helps.

Cold nerves conduct slowly, producing results that mimic real disease. Lewis treats limb temperature as the single most important technical variable — at least 32 degrees in the upper limb before recording — and points out the trap: “if you're in Florida, believe it or not, even though it's warm outside, if they've been waiting in that waiting room for fifteen minutes, they've cooled down.”

Being warmed properly is what stops you being told you have a problem you do not have. It is worth the extra ten minutes.

How to make it easier

• Dress warmly and keep your coat on until you are called.
• No lotion or oil on the skin that day.
• Eat normally and take your usual medication unless told otherwise.
• Say if you have a pacemaker, implanted defibrillator or nerve stimulator, or if you take blood thinners.
• Ask for a pause if you need one. Nothing in the study is harmed by stopping for a moment.
• Drive yourself home. No sedation is used and there is no recovery period.

Afterwards

Normal activity straight away. Some muscle soreness for a day or two and occasional small bruises are the only common after-effects. Paracetamol and a warm compress are enough if you need anything at all.

Results usually go to the doctor who requested the study rather than being given on the day, since interpretation means reading the numbers against your history and examination.