Everyone has heard of the placebo effect: expecting to feel better makes you feel better. Fewer people know its opposite. Expecting to feel worse makes you feel worse. This is the nocebo effect, and it turns up every day in clinics and hospitals, usually by accident.
What it is
“Placebo” comes from the Latin for “I shall please.” “Nocebo” means “I shall harm.” A nocebo effect is a negative outcome produced by negative expectation.
It is a kind of suggestion. When someone in authority tells you that something will hurt, your attention goes to the place, your body braces, and the pain system is primed. The suggestion does not need hypnosis to work. A frightened patient in a medical setting is already highly focused and highly suggestible.
The bee sting study
In one trial, women in labour who were about to have an epidural were given a local anaesthetic injection first. Just before it, they heard one of two statements chosen at random.
- Group one: “You will feel a big bee sting; this is the worst part.”
- Group two: “We are going to give you a local anaesthetic that will numb the area, and you will be comfortable during the procedure.”
The injection was the same. The women who heard about the bee sting reported significantly more pain.
“Can words hurt?”
In another study, researchers analysed recordings of what staff said to patients during procedures in a radiology department, and compared it with the patients’ ratings of pain and anxiety.
Two findings stood out.
- Warning a patient in terms of pain or unpleasantness (“this will sting,” “you’ll feel a burn”) was followed by more pain and more anxiety than saying nothing of the kind.
- Sympathising in the same terms afterwards (“that was the bad part, wasn’t it?”) did not increase pain, but did increase anxiety.
The staff meant well. Preparing someone for discomfort feels like the honest, kind thing to do. The data suggest it backfires.
Where nocebo effects show up
- Injections and procedures
- Side effects. In drug trials, people taking a dummy pill often report the side effects they were warned about.
- Information leaflets listing everything that might go wrong
- A diagnosis delivered bleakly: “You’ll have this for life.”
- Scans and reports: words like “degeneration” and “wear and tear” can make back pain worse by suggesting the spine is fragile.
- What you read online before an appointment
Words that hurt and words that help
| Instead of | Try |
|---|---|
| “This will hurt.” | “You may feel some pressure.” |
| “Sharp scratch!” | “I’m going to start now.” |
| “Don’t worry.” | “You’re doing well.” |
| “This is the worst part.” | “This numbs the area so you’ll be comfortable.” |
| “Are you in pain?” | “How comfortable are you?” |
| “Try not to move.” | “Stay nice and still.” |
| “You won’t feel sick.” | “You’ll feel settled.” |
Three principles sit behind these.
The mind skips “not.” “Don’t worry” plants “worry.” “It won’t hurt” plants “hurt.” Say what you do want.
Describe the sensation neutrally. “Pressure,” “cool,” “a push” inform without alarming.
Give the purpose. “This numbs the area” gives the person something reassuring to hold on to.
But what about honesty?
This is the real difficulty. Patients have a right to know what is going to happen and what the risks are. Nobody is suggesting deceiving them.
The answer is in how the truth is framed, not whether it is told.
- Be accurate and neutral. “Some people feel a sting; many feel very little.”
- Put the positive figure first. “Most people have no side effects” before “a few get a headache.”
- Pair information with what helps. “If you feel anything, slow your breathing and tell me.”
- Ask how much detail the person wants.
That respects consent without priming the worst.
What you can do as a patient
You cannot control what others say, but you can change what you do with it.
- Translate. When you hear “sharp scratch,” think “a moment of pressure.”
- Ask for neutral language. “Please just tell me when you’re starting.”
- Look away and put your attention somewhere specific.
- Breathe out slowly as the needle goes in.
- Give yourself a suggestion: “My arm is loose and comfortable.”
- Be careful what you read beforehand. Use reliable sources and stop when you have enough.
- Remember that a listed side effect is a possibility, not a prediction.
For parents
Children are especially responsive. “It won’t hurt, I promise” tends to fail on two counts: they hear “hurt,” and then it does. Try “You might feel a quick squeeze, and then it’s done. Shall we blow the bubbles?”
The link with hypnosis
Clinicians trained in hypnosis learn to choose words carefully because they know how suggestion works. The radiologist behind the “Can words hurt?” study went on to train whole hospital teams in comforting language, and showed it reduced pain, anxiety and medication. You do not need a trance to benefit from better words.
The bottom line
Words are not neutral. A warning meant kindly can increase pain, and a few changes of phrasing can reduce it. Whether you are giving care or receiving it, it is worth choosing the words on purpose.
Next in the series: Do You Even Need the Induction? Suggestion Without Hypnosis
This article is for general information and is not medical advice.