No anaesthetic is completely free of risk. Side effects such as nausea or a sore throat are common and usually short-lived. Serious complications are rare, but they do happen, and they are more likely with some health conditions and with major or emergency surgery. Your anaesthetist's role is to understand your risks, explain them in plain language, and plan your care to reduce them.
Why there is no simple yes or no
“Is it safe?” is really three questions: safe for whom, for which procedure, and with which kind of anaesthetic. A fit adult having a short planned procedure under sedation faces a very different level of risk from someone with heart disease having major emergency surgery under a general anaesthetic.
That is why Australian guidance from the Australian and New Zealand College of Anaesthetists (ANZCA) asks anaesthetists to discuss the risks that are relevant to each patient, rather than giving everyone the same answer. Written information like this article helps you prepare, but it does not replace that conversation.
What affects your risk
Your health. Heart and lung disease, diabetes, kidney disease, obesity, obstructive sleep apnoea, smoking and vaping, and frailty can all make complications more likely. So can a previous problem with anaesthesia, for you or a blood relative.
Your procedure. Longer and more complex operations, operations with more blood loss, and operations on the heart, lungs, brain or major blood vessels carry more risk than short, minor procedures.
The type of anaesthetic. General anaesthesia, sedation, regional anaesthesia (such as a spinal or nerve block) and local anaesthesia each have their own risks. Sometimes one option suits you better than another, and sometimes a combination is used.
Urgency. Emergency surgery carries more risk than planned surgery, partly because there is less time to prepare and to improve your health beforehand.
How risk is described
Anaesthetists often use words rather than numbers, because the numbers depend so much on the individual. As a general guide:
| Word | What it usually describes | Examples |
|---|---|---|
| Common | Effects many people notice, which usually pass within hours or days | Feeling sick, a sore throat, shivering, drowsiness, bruising where the drip was placed |
| Less common | Problems that happen to a small minority, and can usually be treated | Damage to teeth or lips, breathing problems in recovery, a reaction to a medicine, temporary confusion in older people |
| Rare | Serious events that few people ever experience | Severe allergic reaction (anaphylaxis), awareness during a general anaesthetic, nerve injury, heart attack, stroke or death |
If you would like figures, ask your anaesthetist what the numbers are for someone with your health, having your procedure. Figures that are not matched to you can be misleading in either direction.
How anaesthetists reduce risk
- Assessment before your procedure. Your health, medicines, allergies and previous anaesthetics are reviewed beforehand, so problems can be anticipated and planned for. Read preparing for anaesthesia.
- Choosing the approach that suits you. Sometimes this means a different type of anaesthetic, extra tests, advice to improve a condition first, or a recommendation to have the procedure in a hospital rather than a day facility or dental practice.
- Continuous care. Your anaesthetist stays with you throughout the procedure, watching your breathing, heart rate, blood pressure and oxygen levels with monitoring equipment that ANZCA’s professional documents set out.
- Recovery. You are monitored as you wake up, and only go home once you meet the discharge criteria, with a responsible adult to look after you.
What you can do
- Tell your anaesthetist about every health condition and every medicine you take, including weekly injections, vitamins and herbal products.
- Follow your fasting and medicine instructions exactly. Read fasting before anaesthesia.
- Stop smoking and vaping as early as you can before your procedure. Read smoking, vaping and anaesthesia.
- Tell the hospital or practice if you become unwell in the days before.
- Arrange a responsible adult to take you home and stay with you.
- Ask questions until you understand the plan.
Questions to ask about risk
- What are the most likely side effects for me, and how are they treated?
- Do any of my health conditions make complications more likely?
- Is there another type of anaesthetic I could have, and how do the risks compare?
- Is there anything I can do before the procedure to lower my risk?
- If something unexpected happens, what is the plan?
Making your decision
You can take time to think, talk with your family, and ask for more information before you agree to an anaesthetic. You can also change your mind. If English is not your first language, ask for a professional interpreter. Read what to expect on the day for the full list of common, less common and rare risks.
Sources
- healthdirect Australia. General anaesthetic. Last reviewed Dec 2025.
- ANZCA. About anaesthesia (patient information). Page modified 29 Mar 2026.
- ANZCA. What does an anaesthetist do?. Accessed 2 Nov 2026.
- ANZCA. PS26(A) Position statement on informed consent for anaesthesia or sedation. Apr 2021.
- ANZCA. PG07 Guideline on pre-anaesthesia consultation and patient preparation (2024; Appendix 1, Fasting, revised June 2026). June 2024; Appendix 1 June 2026.
- ANZCA. Professional documents (including PS55 facilities, PG18 monitoring, PS19 monitored care, PS04(A) post-anaesthesia care, PG29(A) children). Accessed 2 Nov 2026.
- Australian Society of Anaesthetists. During your anaesthetic. Accessed 2 Nov 2026.
- Written by
- Altitude Creative, health content team, on behalf of Dr Walid Aly
- Clinical reviewer
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How we write, review and correct this information: editorial policy.
In an emergency, call 000. This information is general and does not replace advice from your treating practitioner.