You and your anaesthetic

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This leaflet gives information on what to expect when having surgery with anaesthesia. It has been written by anaesthetists working together with patients and patient representatives. It also shows you where to find other information that might be helpful.


This leaflet explains:

  • the different types of anaesthetics
  • what happens before the operation
  • how to discuss risks and options with your anaesthetist
  • how to prepare for surgery
  • what happens on the day of the operation
  • what happens after the operation
  • where to find more information.

What is anaesthesia?

Anaesthesia stops you feeling pain and unpleasant sensations. It can be given in various ways and does not always mean that you are asleep.

There are different types of anaesthesia, depending on the way they are given:

Local anaesthesia involves injections that numb a small part of your body and are normally used for relatively minor procedures. You stay conscious but free from pain. This is commonly administered by the surgeon undertaking the operation.

Regional anaesthesia (for example, a spinal, epidural or nerve blocks) involves injections that numb a larger or deeper part of the body. You stay conscious or receive some sedation, but are free from pain. For some surgery you may be aware of pressure sensations.

General anaesthesia is medication that gives a deep sleep-like state. It is essential for some operations and procedures. You are unconscious and feel nothing. Drugs for a general anaesthetic are usually given into a vein or breathed in as a gas, or a combination of both.

Sedation is medication that makes you feel sleepy and relaxed. You will not be completely asleep and you may be aware of your surroundings.

Sedation is often used with a local or regional anaesthetic. Sedation may be light or deep depending on the procedure and you may remember everything, something or nothing after sedation.

For more information about sedation, please see our Sedation explained leaflet which is available on our website.

More information on the different types of anaesthetics can be found here.

About anaesthetists

Anaesthetists are doctors with specialist training who:

  • discuss with you the types of anaesthetic that are suitable for your operation 
  • if there are choices available, will help you choose and discuss the risks, benefits and alternatives with you
  • agree a plan with you for your anaesthetic and pain control afterwards
  • give your anaesthetic and are responsible for your safety and wellbeing throughout your surgery and in the recovery room.

You may also meet other highly trained healthcare professionals. Read more about these roles and the anaesthesia team on our website.

The preoperative assessment clinic (preassessment clinic)

If you are having a planned operation, you might be invited to a preoperative assessment clinic a few weeks or days before your surgery. Sometimes, for more minor surgery, a nurse will telephone you or you may be asked to fill in a questionnaire.

Please bring with you:

  • a list of the medications that you are taking or bring your medicines in their full packaging (you can get a copy of this list from your pharmacist or GP)
  • details of any hormonal contraceptives (tablets or other forms) that you are taking
  • details of any herbal remedies that you are taking
  • any information you have about tests and treatments at other hospitals
  • information about any problems you or your family may have had with anaesthetics
  • any recent blood pressure measurements.

It’s important to have your blood pressure checked at your GP surgery as soon as you know you are going to have an operation. If your blood pressure is high, treatment can be started well ahead of the operation to avoid delays with your surgery. 

Nurses at the clinic will:

  • ask you in detail about your activity and any physical and mental health problems
  • ask you about allergies and reactions (please bring details)
  • make an accurate list of the medicines you take, including long-term painkillers
  • ask you if you smoke, drink alcohol or take recreational drugs
  • weigh you and measure your height
  • take your blood pressure and check your heart rate and oxygen levels
  • listen to your heart and chest if required
  • arrange any blood tests as needed
  • perform an electrocardiogram (ECG) to check your heart if necessary
  • take a skin and/or nose swab to check for any infection
  • advise you on what medication you should take on the day of your surgery and what pain relief you should have ready at home for your recovery
  • give you information about the procedure and any risks 
  • give you information about when to stop eating and drinking.

They may also give you information about blood transfusions if they think you may need one. 

Blood transfusions are always avoided unless necessary. You can also find information about them on the NHS website.

Please read our leaflet Anaesthesia explained if you would like to read more detailed information about anaesthesia.

Meeting your anaesthetist

You may meet with an anaesthetist at the preassessment clinic. Otherwise, you will meet your anaesthetist in the hospital on the day of your surgery. They will discuss the type of anaesthetic you can have, including benefits, risks and your preferences, and you will decide together which anaesthetic is best for you.

However, not all types of anaesthetic are appropriate for all types of operations.

If there is a choice of anaesthetic, the decision on which to use will depend on:

  • the operation you are having 
  • any medical problems and your specific risks
  • your preferences and the reasons for them
  • the recommendation and particular skills of the anaesthetist
  • the equipment, staff and resources at the hospital.

Risk and shared decision-making

Modern anaesthetics are very safe. There are some common side effects from the anaesthetic drugs or the equipment used, which are usually not serious or long lasting. Risks will vary between individuals and will depend on the procedure and anaesthetic technique used.

Your anaesthetist will discuss with you the risks that they believe to be more significant for you. They will only discuss less common risks if they are relevant to you. 

You can read more detail about risks associated with anaesthesia here.

Shared decision-making

Shared decision-making ensures that individuals are supported to make decisions that are right for them. It is a collaborative process through which a clinician supports a patient to reach a decision about their treatment.

The conversation brings together:

  • the clinician’s expertise, such as treatment options, evidence, risks and benefits
  • what the patient knows best: their preferences, personal circumstances, goals, values and beliefs.

Find out more on the NHS England website.

Questions you might like to ask

If you have questions about your anaesthetic, write them down (you can use the examples below and add your own). If you want to speak to an anaesthetist before the day of your operation, contact the preoperative assessment team who may be able to arrange for you to speak to an anaesthetist on the telephone or see them in a clinic.


Do I have any special risks from the anaesthetic?


Will the anaesthetic affect my recovery after surgery?








Preparing for the operation

Fitter patients who are able to improve their health and lifestyle recover from surgery more quickly and with fewer complications.

There is much you can do to prepare yourself for an operation. Even small changes can make a big difference. You might want to increase your levels of physical activity and improve your diet. If you drink or smoke, you should consider cutting back or even stopping. 

If you have a long-standing medical problem, check with your GP surgery whether there is anything you can do to improve it well ahead of the surgery.

Our Fitter Better Sooner resources will provide you with the information you need to become fitter and better prepared for your operation. Please see our website for more information.

On the day of your operation

The hospital should give you clear instructions about when to stop eating and drinking. These instructions are important. If there is food or liquid in your stomach during your anaesthetic, it could come up into your throat and lungs and endanger your life. However, you will be allowed to sip clear liquids up to two hours before the surgery.

If you have diabetes, please check with your hospital about when to stop eating and drinking and how you should take your medication on the day of your operation.

If you are a smoker, you should not smoke on the day of your operation, because this reduces the amount of oxygen in your blood. You should also not vape.

If you are on medication, you should follow the specific instructions from the preoperative assessment team about how to take them on the day of the operation. You will be allowed a sip of water to take any tablets as needed.

If you take any ‘blood-thinning’ drugs such as warfarin, clopidogrel or rivaroxaban, you will need to discuss with your consultant or the preoperative assessment team whether or when you should stop taking them. They will look at any risks of bleeding and risks of stopping the treatment, and make a plan with you. Your nurse will give you clear instructions before your surgery.

If you feel unwell when you are due to come into hospital, please telephone the ward for advice.

Please remove nail varnish, false nails or gels before coming to the hospital. This ensures that the clip on your finger to measure oxygen levels works well during your anaesthetic.

Getting ready for your operation

Your nurse will give you a hospital gown to wear and discuss what underwear you may wear. 

You might be asked to wear elastic stockings to reduce the risk of blood clots in your legs. 

Your nurse will attach identity bands to your wrist or ankle and, in some hospitals, an additional band if you have any allergies.

Premedication (a ‘pre-med’) is sometimes given before some anaesthetics. Pre-meds prepare your body for surgery – they may start off the pain relief, reduce acid in the stomach or help you relax.

A nurse will carry out a pregnancy test on a urine sample if you are a woman of childbearing age. This is standard practice.

You should remove jewellery and/or any decorative piercings. If you cannot remove it, the nurses will cover it with tape to prevent damage to it or to your skin. A wedding ring can usually be worn.

You may be offered a small drink of water. 

When you are called for your operation

A member of staff will go with you to the theatre.

You can usually wear your glasses, contact lenses and hearing aids, and dentures until you are in the anaesthetic room. You may be able to keep them on if you are not having a general anaesthetic.

If you are having a local or regional anaesthetic, you may be able to take your own electronic device, with headphones to listen to music (check with your nurse beforehand).

You may walk to theatre, accompanied by a member of staff, or you may go in a wheelchair or on a bed or trolley. If you are walking, you can wear your own dressing gown and slippers.

Routine checks will be done as you arrive in the operating department before the anaesthetic starts. You will be asked your name, your date of birth, the operation you are having, where on your body you are going to have the surgery, when you last ate or drank and if you have any allergies. These checks are routine in all hospitals.

Starting the anaesthetic

Your anaesthetic may start in the anaesthetic room or in the operating theatre. Your anaesthetist will be working with a trained assistant. The anaesthetist or the assistant will connect monitors to measure your heart rate, blood pressure and oxygen levels, and any other equipment as required.

A cannula, a thin plastic tube, will be inserted in a blood vessel on the back of your hand or arm. This will be used to give the anaesthetic and any other drugs required during and after surgery. If you are feeling anxious about having a cannula inserted, you may be able to have a local anaesthetic cream to numb the area.

General anaesthetics

Anaesthetic drugs are injected into a vein through the cannula. This method is generally used to start the anaesthetic and also to give other medications during surgery. You may also be given oxygen through a mask. 

After you are asleep, a breathing tube will be inserted to give oxygen and anaesthetic gases if required. The breathing tube will be removed before you wake up. 

More information is available in the leaflet Your airway and breathing during anaesthesia

Regional anaesthetics

If you are having a regional anaesthetic, the following will happen:

  • your anaesthetist will ask you to keep still while the injections are given. They may use a special ultrasound machine to place the local anaesthetic. You may notice a warm tingling feeling as the anaesthetic begins to take effect
  • your operation will go ahead only when you and your anaesthetist are sure that the area is numb. They will do several tests to make sure that the anaesthetic is working
  • you will remain alert and aware of your surroundings, unless you are having sedation. A screen will stop you seeing the operation unless you want to and the theatre team agrees that you can watch
  • a member of the anaesthetic team is always near to you and you can speak to them whenever you want
  • you may also be able to listen to music with headphones during the procedure. 

The recovery room

After the operation, you will usually be taken to the recovery room, a special ward close to the operating theatre where you will be closely monitored as you recover from the anaesthetic. Recovery staff will make sure that you are as comfortable as possible and give any extra medication that you may need. When they are satisfied that you have recovered safely from your anaesthetic and there is a bed available, you will be taken back to the ward.

Pain relief after surgery

The type and amount of pain relief you will be offered will depend on the operation you are having and your pain levels after the operation. Some people need more pain relief than others.

Generally, some degree of pain or discomfort should be expected during your recovery. Stronger painkillers can be very good at relieving pain, but may have side effects, like nausea, constipation and addiction in the long term.

You may be offered the following types of pain relief:

  • pills, tablets or liquids to swallow – these are used for all types of pain. They typically take at least half an hour to work. You need to be able to eat, drink and not feel sick for these drugs to work.
  • injections – these may be intravenous (through your cannula into a vein for a quicker effect) or intramuscular (into your leg or buttock muscle using a needle, taking about 20 minutes to work).
  • patient-controlled analgesia (PCA) – this involves a machine with a push button which, when pressed by you, delivers a small dose of strong pain killer directly into your cannula or drip. It is programmed to ensure that you cannot give yourself an overdose. A PCA puts you in direct control of your own pain relief.
  • local anaesthetics and regional blocks including spinals and epidurals – these types of anaesthesia can be very useful for relieving pain after surgery. More details can be found in our leaflets Epidural pain relief after surgery, Your spinal anaesthetic and Nerve blocks for surgery on the shoulder, arm or hand.

Pain relief after leaving hospital

Although you may be given a supply of painkillers when you leave the hospital, it is sensible to buy some over-the-counter painkillers to have ready at home. If you are still needing them two weeks after discharge from the hospital, you should get in touch with your GP to discuss this further.

You may be prescribed painkillers containing opioids after your operation. It is important that you reduce and then stop these medications as soon as possible because their continued use can cause you significant harm.

You can find more information on opioids on the Faculty of Pain Medicine website.

Going home and when to ask for help

You will not be able to drive after surgery, so you should arrange for a taxi or someone to pick you up. 

Before being discharged you will be given information on any exercises you should do to help you recover and information on how to look after your wound.

You should contact your GP or the hospital where you had your surgery if:

  • you have severe pain or your pain increases
  • you develop pain and swelling where you had the surgery
  • you experience chest pain or breathing difficulty
  • you have any concerns that are not covered in the discharge information that you will have been given by the hospital.

If you feel very unwell, you should go to your nearest emergency department as soon as possible.


We try very hard to keep the information in this leaflet accurate and up-to-date, but we cannot guarantee this. We don’t expect this general information to cover all the questions you might have or to deal with everything that might be important to you. You should discuss your choices and any worries you have with your medical team, using this leaflet as a guide. This leaflet on its own should not be treated as advice. It cannot be used for any commercial or business purpose. For full details, please click here.

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Sixth Edition, April 2023
This leaflet will be reviewed within three years of the date of publication.

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