Patient FAQs

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Information about anaesthesia

The aim of a general anaesthetic is to make sure you remain unconscious and in no pain for the duration of your operation. It is a specialised medical procedure and only undertaken by doctors and anaesthesia associates who have been highly trained to do this. Afterwards you should have no memory of what happened under the anaesthetic.

A general anaesthetic is essential for a very wide range of operations. These include operations on the heart or lungs or in the abdomen, and most operations on the brain or the major arteries. It is also normally needed for laparoscopic (keyhole) operations on the abdomen.

Before the operation, drugs will be injected into a vein, or gases will be given for you to breathe. These drugs or gases make you become unconscious and pain-free during surgery.

Find out more information here.

In most hospitals you will be invited to a preoperative assessment clinic some time before your actual operation. At this clinic you will see a preoperative assessment nurse specialist.  An anaesthetist may also see you then, and this is especially likely if you are having a major operation or have any significant medical problems.

Some hospitals may ask that you complete a health questionnaire and it is important that you include any medical issues you may have. The hospital needs to know about your general health, your regular medication, including over-the-counter medications and herbal medicines, and any allergies. Please bring your tablets and any details about allergies. If you have any letters or details of medical tests from other hospitals, these can be very helpful too.

They will also be interested in any anaesthetics you have had previously and how you felt afterwards. If you are aware of any family members who have had a serious reaction to anaesthetics, please ask your relative to tell you more about it and for any details you can show to your anaesthetist.

If you have not seen an anaesthetist at the preoperative assessment clinic, you will still meet them just before your operation.  They will discuss any options with you and will tell you about what they are planning to do.  You can also ask them any questions you might have (see ‘Questions to ask the anaesthetist’ above).

Find out more information here.

For a fit person having a planned procedure under general anaesthetic the risks are very low.

Anaesthesia has been made safer by high standards of anaesthetists’ training and by improvements in drugs and monitoring equipment. An anaesthetist stays beside you all the way through the anaesthetic. They can adjust the dose to give you just the right amount and keep you both asleep and safe.

The Royal College of Anaesthetists has produced a series of leaflets on the risks of anaesthesia that can be viewed here if you want to look at risks in more detail.

It is rare for anyone to be aware during a general anaesthetic. More commonly people may remember the feeling of a tube in the throat being taken out as they wake up.  Some people also have dreams around the time they wake up and are in recovery.

In 2014 the Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland published a very large study of accidental awareness during general anaesthesia. This report showed that accidental awareness happens in only 1 in 20,000 patients during a general anaesthetic. Advances in equipment and in monitoring the level of anaesthesia have helped to reduce the chances of this happening. An anaesthetist will be with you all the time during your surgery and watching all monitoring equipment closely to check you are getting the right amount of anaesthetic to keep you unaware and pain free.

You can find out more about awareness during general anaesthesia here.

Allergic reactions can happen with almost any drug.

Your anaesthetist uses continuous monitoring, which helps make sure that any reaction is noticed and treated before it becomes serious.

It is important to tell your anaesthetist about any allergies you know you have. If there are any that have occurred with anaesthetic drugs, please bring in details of this with you. Some rare serious reactions to anaesthetics run in families, so if any family member has had a serious reaction you should try and find out if they have been given any information on this.

Find out more information here.

There is normally no increased risk in having two anaesthetics close together. This applies whether they are general anaesthetics, local anaesthetics, regional anaesthetics (such as epidurals or spinals), sedation for procedures, or a combination of these. However, it is important to tell your anaesthetist about any recent anaesthetics of any sort and to discuss with them the options for your next anaesthetic.

Suxamethonium (Scoline™) is a muscle relaxant drug that is now only rarely used by anaesthetists in routine operations. However, there are some emergency situations in which it is still the most appropriate choice and it may be used in urgent surgery.

A few people suffer from a condition known as ‘suxamethonium apnoea’. This is a rare, inherited condition. If someone in your family is known to be affected, it may be wise for other members of the family to be screened for it by means of a blood test. Your GP should be able to arrange the blood test after discussion with the anaesthetic department at your local hospital.
When suxamethonium is used, the muscles are profoundly relaxed and the patient is unable to move or breathe for themselves. The effect usually lasts 3-4 minutes. In patients who have suxamethonium apnoea, the effect is prolonged for anything up to 4 hours. All trained anaesthetists are aware of the condition, and in the unlikely event that a patient develops it after being given suxamethonium, breathing is assisted by means of a mechanical ventilator until the drug wears off. The patient is sedated during this time to keep them asleep. There should be no long-lasting effects once recovery is complete.

If you would like information about epidurals and other methods of pain relief in labour, we would advise that you read the information produced by the Obstetrics Anaesthetists’ Association.

This will depend on whether you have eye drops or injections to numb your eye. When anaesthetic eye drops are used, most people are just aware of a bright light from the microscope once the operation starts. You may see some moving shapes, but not the actual operation or the instruments. If your eye is numbed with an injection, you may only see darkness until the injection wears off.

Your surgeon will place a sterile sheet over the eye not having surgery, so you will not be able to see the operation.  If you suffer from claustrophobia, they sometimes will use a clear sheet instead. You may then see people moving around you but you will not be able to see the detail of your operation.

For more details on eye operations please click here

Regional anaesthesia (often abbreviated to RA) and nerve blocks are often used on their own or with some light sedation to help you relax, either by choice or if you  have medical problems that make general anaesthesia more risky. You will feel pressure and vibration but you should not feel pain in the area numbed. 

Regional Anaesthesia means numbing a whole region or large area of your body. Your anaesthetist will inject local anaesthetic around a large nerve or group of nerves. In the back, for example, this is called either an epidural or spinal injection depending upon where your anaesthetist injects the local anaesthetic. It can provide pain relief on its own for operations such as caesarean section, hip or prostrate surgery. Alternatively you may have it as well as a general anaesthetic to help with pain relief afterwards. For example, this may be helpful in major bowel surgery.

A nerve block usually means injecting local anaesthetic around a single nerve.  This numbs just the area controlled by that nerve during and after surgery. The other areas around that nerve will still have normal feeling and normal movement. Your anaesthetist will often use an ultrasound machine to show exactly where your nerves are. During some operations, your surgeon may place a thin plastic tube or catheter near your nerves. After your operation this can continuously bathe your nerves in local anaesthetic for two or three days after your operation to keep your pain well controlled. For more details on regional anaesthesia please see our patient information resources.

Preparing for your operation

As soon as you know that you may be having an operation it is helpful to think about how you can be as healthy and as fit as possible for surgery. If you have existing medical conditions such as high blood pressure and diabetes, you may wish to discuss with your GP how you can make your condition as good as possible before your operation.

Many of the risks of having an operation are increased if you are very overweight. It is therefore important to reduce your weight, if you need to, and do some exercise to increase your fitness level ahead of the operation.

If you smoke, you should consider quitting ahead of your operation. Smoking reduces the amount of oxygen in your blood and increases the risk of breathing and heart problems during and after the operation. On average, smokers stay in hospital longer than non-smokers.

Medical staff understand how hard it can be to give up smoking, particularly at a time when you are likely to be more stressed and anxious.  However, if you can manage to do this you will greatly increase your chance of a speedy and successful recovery.

Find out more information here.

Please avoid wearing makeup on the day you come in for your operation.

Lipstick can make it more difficult for doctors and nurses to see the true colour of your lips. If the level of oxygen in your blood falls, it can change the colour of your lips, so it is important for the medical staff to be able see their natural colour.

Mascara could make your eyes sore if particles of it get into your eyes during the operation.

False eyelashes should be removed before you come into hospital – during an anaesthetic your eyes are kept gently shut using tape and false eye lashes may be damaged. 

During an anaesthetic, your anaesthetist may need to secure equipment to your skin – body lotions, foundation and face cream can make this more difficult as they may prevent heart monitor pads and dressings from sticking properly.

You should also remove nail varnish and, usually, false nails. False nails and varnish may interfere with equipment monitoring the oxygen level in your blood. This is because a finger clip is used that shines a light through your finger nail.

Find out more information here.

While you are anaesthetised you are less able to breathe on your own. The anaesthetist will place a breathing tube in your throat while you are unconscious. This is not always straightforward and damage to your teeth is a possibility, especially if those at the front are already loose or you have caps or crowns that are not as strong.

Ideally, if you have any loose or damaged teeth, you should ask your dentist to look at them before your anaesthetic.

If you have any problems with your jaw, opening your mouth or have a stiff neck, make sure you tell your anaesthetist.

Find out more information here.

You should continue to take your usual medicines up to and including the day of the operation unless you are told not to. You should carefully follow the instructions you have been given by the preoperative assessment clinic.

Look out for specific instructions if you take:

  • drugs to thin your blood, e.g. warfarin, dabigatran, rivaroxaban, clopidogrel, aspirin
  • drugs for diabetes
  • blood pressure pills
  • herbal remedies.

If you have not been given instructions on the above medications, please contact your hospital and remember to take your medication into hospital with you.

Find out more information here.

If there is food or liquid in your stomach while you are anaesthetised, it could come up into the back of your throat and then go into your lungs. This would cause choking or serious damage to your lungs.

The hospital should give you clear instructions about eating and drinking, which you should follow carefully. Usually you should not eat any food for six hours before an operation. You can usually drink water until two hours before your operation, but nothing thereafter.

Find out more information here.

Recreational drugs such as cocaine, marijuana, heroin or the so called ‘legal highs’ can affect the way anaesthetics work, how you react to pain after your operation and can lead to withdrawal problems after your anaesthetic.

You should inform your anaesthetist/preoperative assessment clinic if you have used or regularly use recreational drugs. Ideally you should make sure you do not take any recreational drugs in the days preceding your operation.

Unless very young, it is a good idea to have a conversation with your child about the operation and what they can expect, including the anaesthetic.

The Royal College of Anaesthetists has a section on Information for Children, Parents and Carers, which contains several useful resources to help you prepare your child for the operation, depending on the age of the child.

Yes – It is very important that you let the anaesthetist and preoperative assessment clinic know if you are pregnant or breastfeeding. If you are of childbearing age you will usually have a pregnancy test before a planned operation under general anaesthetic or sedation (carried out on a urine sample).

Your anaesthetist will try to use the drugs that are thought to be the safest available for you and your baby. However, because there may be some risks to the baby of having an anaesthetic or surgery when pregnant, it is advisable only to have essential surgery when pregnant. It is generally agreed that the second trimester (3–6 months) is the safest time and it is best to avoid anaesthetics in the first trimester (up to 12 weeks) if possible.

General anaesthetics do not normally have an effect on breastfed babies. However, some painkillers can pass into breast milk and make the baby feel sleepy. The anaesthetist will make sure that you are prescribed appropriate painkillers if you are breastfeeding.

It is very common to be anxious before an operation. There is much you can do, however, to help yourself at this time.

If it is your first time having an operation, it is usually helpful to find out more about going into hospital. You can also read some information about your operation. There is a lot of information you can read in leaflets or on the internet and  also video clips you can watch. It is important, though, to use reliable and well written information - internet browsers can bring up unreliable information on rare side effects that could scare you unnecessarily. The hospital will give you useful information to read. It will usually also suggest some recommended websites or links that you can visit.

You will usually be invited to see a nurse or anaesthetist for a pre-assessment visit. This is your opportunity to ask questions and say what you are worried about. Consider writing your questions down before you go so you don’t forget them. Don’t worry if you think that your questions aren’t very good, as they are very used to explaining what will happen and the choices you have.
Your nurse will give you an information sheet to remind you of what to do before you go into hospital, as it is easy to forget if you are anxious. If your anxiety is very severe your anaesthetist may sometimes offer you a sedative before your operation. However, it can be difficult to plan the timing of giving these and they may delay your recovery.

If you have mental health problems it is important that you talk to your nurse about these and anything that can make things worse. They can give you advice about your medication as it is often important to continue these whilst you are in hospital. They can help organise any particular support you will need for your time in hospital and, importantly, for when you go home.

In the time before your operation it can help to exercise and eat healthily if you are able to. It is good to spend some time with friends or family and sort out anything important so you do not need to worry about that when you are in hospital. Many people find that yoga or meditation can help - even if you have not tried this before. You may also find that simple breathing exercises help you to feel calm and in control and can be easily done in hospital before or after your operation.

It is useful to plan ahead and organise things to take into hospital to keep your mind occupied. You might want to read a book, listen to music through headphones or take some magazines to read. Try to imagine yourself recovering calmly and doing well – perhaps reward yourself with something special to look forward to when you get home.

For more information, please see the Anaesthesia explained.

What to expect after the operation

After most anaesthetics you will be cared for in a recovery room. This is close to the operating theatre. Staff in the recovery room will usually give you extra oxygen through either a clear face mask or through soft plastic tubes that sits under you nostril. This is routine and does not mean that you are unwell. Staff in the recovery room are also responsible for monitoring your vital signs (such as pulse rate, blood pressure and temperature). They will also ask you how you are and treat any sickness or pain that you may have. Sometimes you may feel a little cold or shivery – if this happens they can give you a warm air blanket to quickly warm you. They will regularly check your wound to check there is no bleeding.

When you first arrive in recovery after a general anaesthetic you will feel fairly drowsy. It is common at this stage to drift off to sleep and perhaps dream. You may be aware of other patients around and the noise of monitors beeping. As you become more alert your nurse will sit you up and talk with you. It is common not to remember a great deal of your time in recovery afterwards.

When your recovery nurse is happy that you are awake, comfortable and all your observations are stable, you will be able to return to your bed on the ward.  Your recovery nurse will hand over all the important information and instructions to the nurse from the ward.  They will continue to check all your vital signs, but less often. Depending on your surgery, they may allow you to have some sips of water before giving you something more to drink and eat. Try and rest at this time. Your nurse will be experienced at knowing how you should progress and will call the ward doctor if she has any concerns.
After major surgery you may need to go from theatre straight to the intensive care unit (ICU) or the high dependency unit (HDU). Your surgeon and anaesthetist will discuss with you beforehand if this is planned.  Sometimes it can become necessary as a result of unexpected events during surgery. The length of time that you spend in ICU or HDU will depend on what type of operation you have had, any complications, and any other health
problems you may have.

Patients in HDU need more care and observation than staff can give on the normal ward, but are normally awake and conscious. Patients in the ICU require close supervision at all times and may be given drugs to keep them unconscious and help with their breathing until they are stable. Your relatives will be able to come and visit you in both the HDU and ICU.

For more information, please see our patient resources.

Your anaesthetist will assess your risk of sickness when they visit you before your operation. There are various ways in which your anaesthetist can reduce your chance of suffering sickness. Many people have no nausea or sickness after surgery. Some people can feel very sick, but there is a wide range of drugs to treat this. Your anaesthetist will also prescribe you drugs to help treat any sickness in case you do develop it after the operation.

Find out more information here.

How you feel afterwards depends mainly on the operation you have had, and on any painkilling medicine that you have needed.

When you first wake up you will feel quite drowsy and the nurse in the recovery area will be giving you some oxygen via a mask and will check your blood pressure and your oxygen levels. The nurse will give you any further drugs you need to keep you comfortable.

Find out more information here.

If you have problems passing urine because of an enlarged prostate, sometimes drugs used during an anaesthetic can make things a little worse in the early period after your anaesthetic. If you are having a day case operation, you will need to pass urine before you are allowed to go home. Occasionally it may be necessary to put in a catheter (a flexible soft tube) into your bladder to drain urine before you can pass urine normally again. This may delay you going home. On occasion, you may need to be seen by a urologist (a doctor who specialises in prostate problems) if difficulties continue. 

Becoming confused is not uncommon after an operation and an anaesthetic, especially in the elderly. Behaviour and memory can be affected and there may be some deterioration in more complex mental functions such as the ability to get dressed or do the crossword. Most people make a full recovery.

Find out more information here.

The effects of anaesthetic drugs may last for around 24 hours, longer for major operations. If the operation can be done as a day case you will need to have an able-bodied adult to take you home and be with you that night. People often underestimate the help that they may need after an operation as they recover.

You should not look after children during this time, use any dangerous equipment or cook. You should also avoid making any important decisions and should be careful not to post anything on social media that you might later regret. 

You may feel tired or even exhausted for some days after the operation. After major surgery this can last weeks or months. This is not due to your anaesthetic, but to the fact that healing after major surgery often leaves patients feeling exhausted.

When you go home depends on how quickly you recover from your surgery and anaesthetic.  Generally the quicker you become mobile again, the less likely you will be to get post-operative complications such as blood clots in your legs and chest infections. It will also help your bowel recover faster and get you back to a normal diet.

You will usually sleep better and feel more relaxed in your own home. However, you will be discharged from hospital only when the doctors are happy that you are ready to go home. This is usually when you are mobile, able to eat and drink, and can control your pain by taking tablets. The decision to discharge you will also depend on the help you have at home and your other medical needs.

When you go home it is important to have rest and allow your body to recover. You should begin gentle activity and carefully follow any exercises you are given. You should slowly increase your activity until you are back to your normal fitness levels.

The hospital will give you a number to contact if you have any concerns about your recovery when you first go home.

For more information on how to manage pain after surgery, please see the leaflet from the British Pain Society: Understanding and managing pain after surgery.

Enhanced recovery is the name given to a programme that aims to get you back to your normal health as quickly as possible after a major operation. Hospital staff look at all the evidence of what you and they can do before, during and after your surgery to help give you the best quality recovery.  This should get you home sooner.

The programme will vary depending on what operation you are having but may include:  

  • improving your fitness levels before your operation if enough time
  • treating any other long term medical conditions
  • reducing the time you are starved for by giving carbohydrate drinks before your surgery
  • giving  you drugs to prevent sickness after surgery
  • considering the best ways of giving pain relief during the operation. Using local anaesthetic blocks or regional anaesthetics where possible
  • giving  the best pain relief afterwards to get you moving quicker
  • allowing you to start drinking earlier
  • reducing the time you have catheters and drips in you
  • teaching you  exercises to help you recover after your operation.

By following an enhanced recovery programme, there are usually fewer complications after surgery. There is also less chance of you needing to go back into hospital because of these.

Further information on recovering from surgery is available from the Royal College of Surgeons of England website.

The effects of anaesthetic drugs may last for around 24 hours, longer for major operations. If the operation can be done as a day case you will need to have an able-bodied adult to take you home and be with you that night. People often underestimate the help that they may need after an operation as they recover.

Following any general anaesthetic or sedation, you must not drive for at least 24 hours. This is because the drugs given during your anaesthetic or sedation can affect how you think and make decisions. It takes at least 24 hours for your body to get rid of these medicines.

It may take longer to recover from your surgery than your anaesthetic. Your surgeon will give you advice on when it should be safe for you to drive after your procedure or operation.

However before getting back in the driving seat, you will need to be sure that you can brake and drive safely without being distracted by pain.

If you are taking strong painkillers you also need to be aware that these can make you feel drowsy and affect your driving.

By law, you need to decide whether you think you can drive safely. If you feel drowsy, distracted by pain or generally unwell, you’ll need to wait a little longer until it is safe for you to drive.

You should check with your insurance company that you are covered to drive after your surgery.

Check with DVLA about any specific time periods recommended – information can be found on the DVLA website.


Enquiries to the Royal College of Anaesthetists

The RCoA cannot give advice to individuals regarding their personal treatment.  If you are writing to the RCoA please note that we are unable to reply immediately. The RCoA often uses specialist advisors to answer enquiries and this may delay a response.  For any immediate medical concerns you should contact your GP or the emergency services without delay. Should you need more specific advice regarding your treatment, you are advised to contact the hospital where you are being treated.

The RCoA publishes a comprehensive series of Patient Information leaflets offering information on the different types of anaesthetics and the likely risks. We would advise you to take a look at these leaflets as they may contain the information you are looking for. You can see the full series here.

No, the RCoA cannot recommend or vouch for individual anaesthetists.

Information on individual medical practitioners and their registration is held by the General Medical Council and can be accessed by members of the public here.

No. The RCoA does not hold lists of experts to provide a medico legal opinion.

The role of the RCoA is to educate and train anaesthetists and to set the standards for the specialty.

The RCoA is not a regulator and cannot act on complaints raised by patients. For a list of regulators and advice on how to complain about your treatment please visit the Complaints about your Doctor or Treatment page.

Questions you may want to ask your anaesthetist or the nurse at your preoperative visit or assessment

It may be helpful to try and get the answers to any questions you might have well in advance of your scheduled surgery. Below is a list of issues you may wish to discuss with your anaesthetist or nurse. Alternatively, there are some more specific patient FAQs above that may help you. If you have any further general requests or queries concerning anaesthesia, please contact However, please note that the College cannot give advice to individuals concerning their treatment.

  1. If I have a cold should I let you know before I come in?
  2. Should I take my normal medication on the day of the operation?
  3. When should I stop eating and drinking?
  4. I’m rather nervous; can I have a premed?
  5. I don’t like needles; do I have to have an injection?
  6. I’ve been told I have poor veins when I go for blood tests, will that be a problem?
  7. I am a diabetic. How do I control my blood sugar before and afterwards?
  8. Are there any particular risks from the anaesthetic for me?
  9. May I leave my false teeth in?
  10. Do I need to remove my hearing aids?
  11. How soon will the feeling return after a regional anaesthesia or nerve block?
  12. What painkillers should I have at home?
  13. When can I drive after an operation?
  14. Can I go home alone following my anaesthetic?