If something goes wrong when you are having medical treatment, this is sometimes called a 'medical accident' or 'adverse event'. If your treatment has not worked or there have been complications, it does not always mean that there has been a mistake, or that someone is to blame. In some cases, you have to accept errors or complications as unavoidable risks of the treatment and the doctor or other healthcare professional would not be considered to blame. For example, if you have major heart surgery, there are risks because of the surgery. However, there can be complications with minor procedures too.
'Clinical negligence' is the legal term used to describe a medical accident where a patient has been harmed, not because of an unavoidable complication, but because a doctor or other healthcare professional has not given the proper standard of care. It doesn't mean that this person was incompetent. It can just mean that in particular case, they made a mistake which they shouldn't have. Clinical negligence includes things like:
Clinical negligence can also include not doing things that should be done, such as: