General Anaesthetics

Overview

A general anaesthetic is a mix of medicines that makes you go into a deep, temporary sleep so you feel nothing during an operation or procedure. It is given by a specially trained doctor called an anaesthetist. While you are asleep, the anaesthetist stays with you the whole time, watching your breathing, heart rate and blood pressure and adjusting the medicines to keep you safe and comfortable. When the operation is finished, the medicines are stopped and you gradually wake up. You will not remember the operation itself.

Very common. Millions of general anaesthetics are given worldwide every year, and most people recover well with no lasting problems.

Anyone of any age can have a general anaesthetic, from babies and children to older adults. It is tailored to each person, so the dose and type of medicine are chosen based on your age, weight, health and the operation you need.

Symptoms

Common symptoms

• Feeling sleepy, groggy or 'foggy' for a few hours after waking up
• A sore throat, dry mouth or hoarse voice (often from the breathing tube or mask)
• Feeling sick (nausea) or being sick, which usually settles quickly
• Shivering or feeling cold just after waking
• Headache, dizziness or blurred vision for a short time
• Aches and pains, or a bruise where the drip or needle went in
• Tiredness and poor concentration for a day or two
• Feeling emotional or tearful for a short while as the medicines wear off

Symptoms in children

• Being unsettled, clingy or crying more than usual when waking up
• Confusion or brief agitation (sometimes called emergence delirium) that settles within minutes to hours
• Feeling sick or refusing food and drink for a short time
• Sleepiness for the rest of the day, with a return to normal play the next day in most cases

Symptoms in older adults

• Confusion or memory problems for a few days after surgery, which usually improves
• Greater tiredness and a longer recovery time
• A higher chance of dizziness, which can increase the risk of falls — take care when standing up
• Temporary worsening of existing memory or thinking difficulties

Causes

Main causes

• You need an operation or procedure that would be too painful, too frightening or unsafe to do while you are awake
• The procedure needs you to be completely still, such as certain types of surgery
• Your doctor needs to protect your breathing and control it during the operation
• A regional or local anaesthetic is not suitable or not possible for your particular operation

Risk factors

• Smoking — stopping before surgery lowers the risk of chest and wound problems
• Being overweight, which can affect breathing and anaesthetic dosing
• Long-term conditions such as heart, lung, kidney or liver problems
• Diabetes, especially if blood sugar is not well controlled
• Previous reactions or problems with anaesthesia, or a family history of these
• Sleep apnoea (a condition where breathing pauses during sleep)
• Being older, which can mean a slower recovery and more confusion afterwards
• Certain rare inherited conditions that affect how the body reacts to anaesthetic medicines
• Allergies to medicines, including antibiotics or pain relief

When to see a doctor

See a doctor urgently if:

• You develop a fever, spreading redness or pus around your wound
• You cannot keep fluids down or feel very unwell after going home
• You have new shortness of breath or chest pain
• You feel confused, very drowsy or cannot stay awake
• You have severe pain that your prescribed pain relief is not helping

Book a routine appointment if:

• You have questions about your anaesthetic before your operation
• You have had a bad reaction to anaesthesia in the past, or a relative has
• You take regular medicines, including blood thinners or herbal remedies — ask before your surgery
• You are pregnant or think you might be
• You have a cold, cough or fever in the days before surgery
• Mild side effects such as sore throat, tiredness or feeling sick last longer than a few days
• You have ongoing memory or concentration problems after surgery

Diagnosis

You do not 'catch' a general anaesthetic — it is a planned treatment. Instead, your team assesses whether it is safe and suitable for you. This is called a pre-anaesthetic assessment. You will be asked about your health, past operations, allergies, medicines and any family history of problems with anaesthesia. Your weight, blood pressure, heart and breathing will be checked, and sometimes an airway examination (looking at your mouth and neck) helps the team plan how to keep your breathing safe.

Tests that may be done

• A talk through your medical history, medicines and allergies
• Blood pressure, pulse, oxygen level and temperature checks
• Listening to your heart and lungs
• An airway check — opening your mouth and moving your neck
• Blood tests, an ECG (heart tracing) or a chest X-ray if needed for your health or operation
• A pregnancy test where relevant
• Review of any previous anaesthetic records

What to expect at your appointment

The assessment may happen in a clinic beforehand or on the day of surgery. It usually takes 15 to 30 minutes. You will be able to ask questions and talk about any fears. You will also be given clear instructions about when to stop eating and drinking before your operation — following these is important for your safety.

Treatment

A general anaesthetic is given in three stages: going to sleep (often through a small tube in your hand or by breathing gas), staying safely asleep during the operation while your anaesthetist monitors you closely, and waking up afterwards in a recovery area. The team also gives pain relief and anti-sickness medicines as needed. You will be watched until you are fully awake, then moved to a ward or allowed home.

Self-care at home

• Follow the fasting instructions exactly — usually no food for a set number of hours and no clear drinks for a shorter time before surgery
• Take your usual medicines unless your team tells you to stop any — ask about blood thinners and herbal supplements
• Arrange for a responsible adult to take you home and stay with you for the first 24 hours if you are having day surgery
• Do not drive, cycle, operate machinery, sign legal documents or make important decisions for at least 24 hours
• Do not drink alcohol for at least 24 hours
• Rest and build up gently — start with light meals and plenty of fluids
• Keep your wound clean and dry as advised, and take pain relief as directed by your team
• Write down any questions or side effects so you can mention them at your follow-up

Medical treatments

There are several types of anaesthetic medicines, and the anaesthetist chooses and combines them for your specific needs. Some are given into a vein, some are breathed in, and some are used to relax muscles or to ease pain and sickness afterwards. All are given in a controlled, monitored setting by a trained doctor. You will not be asked to choose or manage these medicines yourself — your anaesthetist will explain the plan and answer your questions. Tell them about all medicines, supplements and recreational drugs you use, because these can interact with anaesthetic medicines.

When is surgery considered?

Surgery or a procedure is recommended when it is the best way to diagnose or treat your condition. Your surgical and anaesthetic teams will discuss the benefits and risks with you, including the option of not going ahead. If you have a cold, chest infection or fever close to your operation date, contact the hospital — it may need to be postponed.

Living with this condition

For most people, the effects of a general anaesthetic pass within 24 to 48 hours. Plan a quiet couple of days after surgery with help at home if you can. Build activity back up gradually, and expect to feel more tired than usual for a short while. Follow any specific instructions from your surgical team about wound care, activity and returning to work.

Lifestyle tips

• Stop smoking before surgery if you can — even a few weeks helps your lungs and healing
• Keep alcohol to a minimum while you recover
• Keep taking gentle movement, such as short walks, once you feel able
• Eat regular, balanced meals and drink enough fluids to help healing
• Get plenty of sleep and rest in the first few days
• Avoid strenuous activity, heavy lifting and swimming until your team says it is safe

Diet and exercise

Start with light, easy-to-digest foods and sip fluids regularly after your operation. If you feel sick, try small amounts more often. Once you feel ready, gentle walking helps your circulation and reduces the risk of blood clots. Build up slowly and follow any advice from your surgical team about lifting, driving and returning to exercise.

Mental health and emotional wellbeing

It is very normal to feel anxious before an operation, and some people feel low, tearful or 'not themselves' for a few days afterwards. This usually settles. Talk to your team about any worries beforehand — they can explain what will happen step by step. If you feel persistently low, anxious or unlike yourself, tell your GP or surgical team. If you ever feel unable to cope or have thoughts of harming yourself, contact your local crisis or emergency service straight away.

Prevention

A general anaesthetic is not something you can prevent — it is a treatment given when you need it. What you can do is lower the risk of complications. Be honest and complete about your health, medicines and allergies, follow fasting instructions exactly, stop smoking if possible, and get long-term conditions such as diabetes or high blood pressure as well controlled as you can before surgery.

Screening programmes

Before any operation you will have a pre-anaesthetic assessment. This is a chance to spot problems early and plan around them. Bring a list of all your medicines, including anything you buy over the counter, herbal remedies and supplements.

Complications

If left untreated

• This section works differently for anaesthesia — the main risks are complications during or after the procedure, not from leaving a condition untreated.
• Feeling sick, shivering, sore throat or headache for a short time after waking
• Confusion, especially in older adults, which usually improves over days
• Chest infection or breathing problems, more likely in smokers or people with lung disease
• Blood clots in the legs or lungs after surgery, which the team works to prevent
• Awareness during anaesthesia — being conscious during the operation — which is rare but distressing; tell your team if you have experienced this before
• Rare serious reactions, including severe allergic reactions or problems with the heart or breathing, which the anaesthetist is trained to manage

Long-term outlook

For the great majority of people, a general anaesthetic is safe and recovery is straightforward. Modern monitoring and careful planning mean serious problems are uncommon. Your anaesthetist will talk with you about your own risks and how they will be reduced, so you can make an informed choice about your operation.

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