What happens before an operation, and how do I prepare?
The pre-assessment appointment, what to tell them, the fasting rules, what to take with you, and the questions worth asking before you consent to anything.
- Difficulty
- beginner
- Time
- 9 min
- Read
- 5 min
- Safety
- caution
Short answer
Expect a pre-assessment appointment: health questions, medicines, allergies, and often bloods, an ECG or swabs. Tell them everything you take, including supplements. Follow the fasting instructions exactly. Arrange your journey home and someone to stay with you if you are having a general anaesthetic. Ask what the operation involves, what the alternatives are, what recovery looks like and what could go wrong — before you sign the consent form.
An operation is one of the few things in life where the preparation is genuinely as important as the event, and where a small omission — an unmentioned supplement, a cup of tea at the wrong time — cancels the day. It is also a situation where people are given a consent form and feel awkward asking questions, which is exactly backwards.
Safety
Step by step
- Expect a pre-assessment appointment.Usually a few weeks before. Health questions, a medicines review, allergies, and often blood tests, an ECG, height and weight, and swabs to check for MRSA. It exists to find problems while there is still time to deal with them.
- Take a complete list of your medicines.Everything: prescriptions, anything bought over the counter, vitamins, supplements and herbal products. Blood thinners, diabetes medicines, some herbal products and some contraceptives all need specific management before surgery.
- Declare everything they ask about honestly.Smoking, alcohol, recreational drugs, sleep apnoea, loose teeth or caps, previous anaesthetic problems, and family reactions to anaesthetic. All of them change the plan, and none of them is a reason for anyone to think less of you.
- Follow the fasting instructions exactly.You will be told when to stop eating and when to stop drinking, and the two times are usually different. Getting this wrong is one of the commonest reasons operations are cancelled on the day.
- Sort out the logistics before the day.How you will get home — not driving yourself after a general anaesthetic — and who will be with you for the first 24 hours. Time off work, childcare, pet care, and anything you will not be able to lift or reach afterwards.
- Prepare the house for coming back to it.Easy food in, things you use moved to waist height, a clear route to the bathroom, and whatever you were told you will need — a raised seat, a frame, dressings. It is far easier before than after.
- Ask the questions before you consent.What exactly is being done and why. What the alternatives are, including doing nothing. What the recovery looks like, week by week. What the common complications are and what the serious ones are. How long before you can drive, work, lift or fly. Write them down beforehand.
- Take the right things with you.Your medicines in their boxes, the list, your admission letter, glasses and hearing aids and their cases, loose comfortable clothes, and something to do. Leave valuables and jewellery at home.
- Know what to do if you become unwell beforehand.A cold, a chest infection, a skin infection near the operation site or a stomach upset can all mean postponing. Ring the number on your letter rather than turning up and hoping — they would far rather know in advance.
Tips
- Take a written list of questions in. Everyone forgets them in the room, and nobody minds you reading from a piece of paper.
- Ask for the answer in writing where it matters, particularly the recovery timeline and the driving restriction — insurers care about the latter.
- Stopping smoking even a few weeks before an operation measurably improves healing and reduces chest complications. It is one of the few things entirely within your control.
Common mistakes
- Not mentioning supplements — Several affect bleeding or interact with anaesthetic drugs. People leave them out because they do not think of them as medicines, and they are exactly what the question is about.
- Having a cup of tea in the morning — Fasting instructions cover drinks as well as food, with separate timings. A drink at the wrong time can cancel the operation and lose the slot.
- Planning to drive yourself home — After a general anaesthetic or sedation you cannot drive, and the day surgery unit will not discharge you to do so. Arrange it in advance rather than on the ward.
- Signing the consent form without asking anything — Consent is meant to be informed. The questions above are routine and expected, and the team would rather answer them than have you unclear about what is happening.
If it doesn't work
The operation was cancelled on the day
Cause: An emergency taking the theatre, a bed shortage, or something found at the final check — Fix: Frustrating and common. Ask before you leave when it will be rebooked and who to chase, and get a name. Ask whether the pre-assessment tests will still be valid.
You are on a waiting list and have heard nothing
Cause: Waiting lists are long and communication is patchy — Fix: Ring the hospital booking team, not the GP, and ask where you are. You can also ask about the arrangements for choosing a different provider, which exist in England.
You are unsure whether to have the operation at all
Cause: A genuine decision rather than a formality — Fix: Ask for the alternatives and for the option of doing nothing to be explained, and ask how urgent the decision is. Asking for more time, or a second opinion, is a normal request.
Questions people ask
Can I take my regular medicines on the morning?
Some yes, some no, and the pre-assessment team will tell you which and with how much water. Do not decide this yourself.
Can I ask for a second opinion?
Yes. There is no formal right to one, but it is a normal and frequently granted request, made through your GP or the consultant's team.
How long before I can drive?
It depends on the operation and the anaesthetic, and it is really about whether you could perform an emergency stop safely and whether your insurer accepts you are fit. Ask for it specifically, and check with your insurer.
What if I am nervous about the anaesthetic?
Say so. You will normally meet the anaesthetist beforehand, and anxiety about anaesthesia is common and something they deal with routinely. It is a better conversation to have in advance than on the trolley.