Clinical negligence A–Z

Plain-English explanations of terms used in clinical negligence, NHS complaints and the claims process. Longer explanations link to the relevant RemedyBridge guides.

164 terms

A

Access to Health Records Act 1990

The legislation providing a route to certain health records after a patient has died. Relevant applicants include the deceased’s personal representative and, subject to statutory restrictions, a person who may have a claim arising from the death.

Read more: Getting your medical records

Accrual

Explained in: Clinical negligence time limits

Actual knowledge

Explained in: Clinical negligence time limits

Admission

A statement accepting a fact, allegation or part of a case. An admission can concern breach, causation, injury or another issue and can be complete or partial; whether it is intended to be binding can matter.

ADR

Explained in: How a clinical negligence claim works

Advocacy provider

Explained in: Free NHS complaints advocacy in England

Advocate

Explained in: Llais: free complaints advocacy in Wales

Alternative dispute resolution

Ways of resolving or narrowing a dispute without asking a judge to decide every issue at trial. Examples include negotiation, mediation and early neutral evaluation. It is commonly abbreviated to ADR.

B

Bailey

Explained in: Causation in clinical negligence

Balance of probabilities

The civil standard of proof. A fact is generally proved if the court considers it more likely than not to be true. It does not require proof beyond reasonable doubt.

Binding admission

Explained in: How a clinical negligence claim works

Bolam test

A traditional test for professional negligence: a clinician is not ordinarily negligent if acting in accordance with a responsible body of professional opinion, subject to the court’s ability under Bolitho to examine whether that opinion is logically defensible.

Bolitho

The principle that a court is not required to accept a professional practice merely because a responsible body of experts supports it. The professional opinion relied upon must also withstand logical analysis.

Breach of duty

A failure to meet the standard of care the law required in the circumstances. Proving that treatment had a poor outcome does not by itself prove that the duty was breached.

But for test

The usual starting point for causation: would the injury probably have happened but for the negligent act or omission? If the same outcome would probably have occurred anyway, ordinary factual causation may not be established.

C

Care Quality Commission

Explained in: Complaining to your ICB: provider or commissioner?

Case management

Explained in: How a clinical negligence claim works

Causation

The legal connection between a breach of duty and the injury claimed. A claimant must usually prove that the negligent act or omission actually caused relevant injury or loss, not merely that the care was substandard.

Cause of action

Explained in: Clinical negligence time limits

Chester v Afshar

Explained in: Causation in clinical negligence

Claim form

Explained in: How a clinical negligence claim works

Clinical Disputes Protocol

Explained in: What is clinical negligence?How a clinical negligence claim works

Clinical judgment

Explained in: Breach of duty in clinical negligence

Clinical negligence

A type of negligence claim concerning healthcare. A claimant generally needs to prove that a healthcare professional or provider owed a duty of care, breached that duty, and caused injury or loss as a result.

D

Damages

Explained in: NHS Wales redress and the £50,000 limitWhat is clinical negligence?

Data (Use and Access) Act 2025

Explained in: Getting your medical records

Data controller

Explained in: Getting your medical records

Data Protection Act 2018

Explained in: Getting your medical records

Date of knowledge

A statutory concept that can determine when the three-year limitation period begins. It concerns knowledge of specified facts about the injury and its possible cause; the claimant does not need to know that those facts amount to negligence in law.

Defence

Explained in: How a clinical negligence claim works

Delegated commissioning

Explained in: Complaining to your ICB: provider or commissioner?

Deliberate concealment

A specific limitation concept under section 32 of the Limitation Act 1980. Where relevant facts have been deliberately concealed, limitation may be postponed. Missing information, poor records or ordinary mistakes do not automatically amount to deliberate concealment.

Direct commissioning

Explained in: Complaining to your ICB: provider or commissioner?

Directions

Explained in: How a clinical negligence claim works

Disability

Explained in: Clinical negligence time limits

Disclosure

The court-governed process for identifying and, where appropriate, allowing inspection of relevant documents. It is broader than obtaining medical records and is subject to rules including relevance, control and legal privilege.

Duce

Explained in: Causation in clinical negligence

Duty of candour

Explained in: Complaining about NHS care in WalesListening to People explainedNHS Wales redress and the £50,000 limit

Duty of care

The legal duty to take reasonable care to avoid causing foreseeable harm. In clinical negligence cases, the existence of a duty between a healthcare professional and patient is often straightforward; breach and causation are usually more disputed.

E

Early resolution

Explained in: Complaining about NHS care in WalesListening to People explained

Estate claim

Explained in: Clinical negligence time limits

Expert evidence

Independent professional opinion used where the court or parties need specialist knowledge. Clinical negligence investigations commonly require expert evidence on breach of duty, causation, condition, prognosis or other medical issues.

Expert report

Explained in: How a clinical negligence claim works

Expert witness

A person permitted to give independent opinion evidence within their specialist expertise. In court proceedings, an expert’s overriding duty is to help the court rather than to advocate for the party who instructed or pays them.

F

Factual causation

Explained in: Causation in clinical negligence

Fatal Accidents Act claim

Explained in: Clinical negligence time limits

Final response

Explained in: Complaining about NHS care in EnglandThe Parliamentary and Health Service Ombudsman

Final-stage complaint

Explained in: The Parliamentary and Health Service Ombudsman

Financial redress

Explained in: NHS Wales redress and the £50,000 limit

Financial remedy

A payment recommended through a complaints or redress process to address financial loss or another injustice. It should not be confused with damages assessed in a civil clinical negligence claim.

Formal investigation

Explained in: Complaining about NHS care in WalesListening to People explained

Formal NHS complaint

Explained in: PALS: help with NHS concerns in EnglandFree NHS complaints advocacy in England

G

Gregg v Scott: Explained in: Causation in clinical negligence

H

Hardship: Explained in: The Parliamentary and Health Service Ombudsman
Health data: Explained in: Getting your medical records
Health record: Explained in: Getting your medical records
Healthcare provider: Explained in: Complaining to your ICB: provider or commissioner?
Healthwatch: Explained in: Complaining about NHS care in EnglandPALS: help with NHS concerns in EnglandFree NHS complaints advocacy in England

I

ICB

Explained in: Complaining about NHS care in EnglandComplaining to your ICB: provider or commissioner?

Independent advocacy

Explained in: Llais: free complaints advocacy in WalesFree NHS complaints advocacy in England

Informed consent

Explained in: What is clinical negligence?Breach of duty in clinical negligence

Injustice

Explained in: The Parliamentary and Health Service Ombudsman

Integrated care board

An ICB is an NHS organisation that plans and commissions most local NHS services in England. It can receive complaints in its role as commissioner but is different from the hospital, GP practice or other provider that delivered the care.

Investigation

Explained in: Public Services Ombudsman for Wales

Issue proceedings

Explained in: Clinical negligence time limits

J

Joint statement: Explained in: How a clinical negligence claim works
Jurisdiction: Explained in: Public Services Ombudsman for Wales

L

Legal advice

Explained in: NHS Wales redress and the £50,000 limit

Legal causation

Explained in: Causation in clinical negligence

Legal remedy

Explained in: The Parliamentary and Health Service Ombudsman

Letter of Claim

The formal pre-action letter setting out the claimant’s allegations, the alleged injury and causation, and other relevant information. It is not a court claim form and sending it does not itself commence proceedings.

Letter of Notification

An optional early pre-action letter notifying a defendant that a clinical negligence claim is likely to follow. It can allow an earlier investigation to begin but is not a Letter of Claim and does not start court proceedings.

Letter of Response

The defendant’s reasoned response to a clinical negligence Letter of Claim. Under the Clinical Disputes Protocol it is normally provided after the defendant’s investigation and should identify what is admitted, denied or otherwise disputed.

Limitation

The law governing how long someone has to start court proceedings. Clinical negligence claims are usually subject to a three-year period, but the starting point and special rules for children, capacity, deaths and other situations can change the calculation.

Limitation Act 1980

Explained in: Clinical negligence time limits

Limitation defence

Explained in: Clinical negligence time limits

Limitation period

Explained in: What is clinical negligence?Clinical negligence time limits

Listening discussion

Explained in: Complaining about NHS care in WalesListening to People explained

Listening to People

Explained in: Complaining about NHS care in WalesListening to People explainedLlais: free complaints advocacy in Wales

Litigation capacity

Explained in: Clinical negligence time limits

Litigation friend

A person who conducts court proceedings on behalf of a child or protected party who cannot conduct the proceedings personally. The litigation friend must act fairly and competently in that person’s interests.

Llais

Explained in: Complaining about NHS care in WalesLlais: free complaints advocacy in Wales

Local authority

Explained in: Free NHS complaints advocacy in England

Logical analysis

Explained in: Breach of duty in clinical negligence

Loss of chance

Explained in: Causation in clinical negligence

M

Maladministration

Explained in: Public Services Ombudsman for Wales

Material contribution

A causation principle that can apply in certain cases involving cumulative causes of a single injury. It can be enough to prove that the negligent factor made a material, rather than negligible, contribution to that injury.

Material increase in risk

Explained in: Causation in clinical negligence

Material risk

A treatment risk is material if a reasonable person in that patient’s position would likely attach significance to it, or if the clinician knows or should know that the particular patient would likely consider it significant.

McCulloch

Explained in: Breach of duty in clinical negligence

Mediation

Explained in: How a clinical negligence claim works

Medical chronology

A date-ordered account of relevant medical events built from records and other evidence. It helps organise an investigation but is not itself proof that negligence occurred.

Medical Examiner

Explained in: Llais: free complaints advocacy in Wales

Medical negligence

A commonly used term for clinical negligence. The expressions are often used interchangeably, although clinical negligence is broader because healthcare can be provided by professionals other than doctors.

Read more: Getting your medical records

Mental Health Act complaint

Explained in: Complaining to your ICB: provider or commissioner?

Montgomery

The Supreme Court authority establishing that patients must be given information about material risks of recommended treatment and reasonable alternatives so that they can make an informed decision about their care.

Multiple possible causes

Explained in: Causation in clinical negligence

N

Next of kin

Explained in: Getting your medical records

NHS complaint

A formal process for raising concerns about NHS-funded care. It can seek investigation, explanations and remedies, but it is separate from a clinical negligence claim and does not itself stop a civil limitation period.

NHS complaints advocacy

Free independent support for someone making or considering an NHS complaint in England. An advocate can help organise and communicate the complaint but does not investigate it, decide the outcome, or provide medical or legal advice.

NHS concern

Explained in: Complaining about NHS care in WalesListening to People explainedPALS: help with NHS concerns in England

NHS continuing healthcare

Explained in: The Parliamentary and Health Service Ombudsman

NHS England

Explained in: Complaining about NHS care in England

NHS redress

Explained in: Public Services Ombudsman for Wales

NHS-funded care

Explained in: Complaining about NHS care in EnglandFree NHS complaints advocacy in England

O

Ombudsman: Explained in: Public Services Ombudsman for WalesThe Parliamentary and Health Service Ombudsman

P

PALS

The Patient Advice and Liaison Service, a free and confidential service commonly available through NHS hospitals in England. It can help with concerns and information but is not the same as formal complaints advocacy or a clinical negligence service.

Parliamentary and Health Service Ombudsman

The PHSO, the independent final-stage body for unresolved NHS complaints in England. It can investigate qualifying complaints and recommend remedies, but it does not decide clinical negligence damages in the same way as a court.

Part 36 offer

A formal settlement offer made under Part 36 of the Civil Procedure Rules. It can be made before or after proceedings begin and may have significant costs consequences depending on acceptance and the eventual outcome.

Particulars of Claim

Explained in: How a clinical negligence claim works

Patient Advice and Liaison Service

Explained in: PALS: help with NHS concerns in England

Personal data

Explained in: Getting your medical records

Personal representative

Explained in: Clinical negligence time limitsGetting your medical records

PHSO

Explained in: Complaining about NHS care in EnglandThe Parliamentary and Health Service Ombudsman

Pre-Action Protocol

Explained in: Clinical negligence time limitsHow a clinical negligence claim works

Primary care

Explained in: Complaining about NHS care in EnglandComplaining to your ICB: provider or commissioner?

Privilege

Explained in: How a clinical negligence claim works

Professional practice test

Explained in: Breach of duty in clinical negligence

Protected party

A person who lacks capacity to conduct court proceedings within the meaning of the Mental Capacity Act 2005 and CPR Part 21. A protected party normally conducts litigation through a litigation friend.

Provider

Explained in: Complaining about NHS care in England

Public Services Ombudsman for Wales

Explained in: Complaining about NHS care in WalesLlais: free complaints advocacy in WalesPublic Services Ombudsman for Wales

Putting Things Right

Explained in: Complaining about NHS care in WalesListening to People explained

Q

Qualifying liability: Explained in: Listening to People explainedNHS Wales redress and the £50,000 limit

R

Reasonable alternative treatment

A clinically reasonable alternative to the proposed treatment. Which alternatives are reasonable is assessed by reference to professional practice; reasonable alternatives must then be discussed with the patient as part of informed decision-making.

Recommendation

Explained in: Public Services Ombudsman for WalesThe Parliamentary and Health Service Ombudsman

Redaction

Explained in: Getting your medical records

Redress

Explained in: Complaining about NHS care in WalesListening to People explainedNHS Wales redress and the £50,000 limit

Rehabilitation

Explained in: How a clinical negligence claim works

Response period

Explained in: Complaining about NHS care in England

Responsible body of professional opinion

Explained in: Breach of duty in clinical negligence

Right of access

Explained in: Getting your medical records

S

SAR

Short for subject access request. A SAR does not require special wording and can be used by a living person to exercise their data-protection right of access to personal information.

Read more: Getting your medical records

Secondary care

Explained in: Complaining about NHS care in EnglandComplaining to your ICB: provider or commissioner?

Section 33 discretion

The court’s power under section 33 of the Limitation Act 1980 to allow certain personal-injury claims to proceed despite expiry of the ordinary limitation period where it is equitable to do so after considering all the circumstances.

Serious harm test

Explained in: Getting your medical records

Service failure

Explained in: Public Services Ombudsman for Wales

Settlement

Explained in: NHS Wales redress and the £50,000 limit

Significant injury

Explained in: Clinical negligence time limits

Special report

Explained in: The Parliamentary and Health Service Ombudsman

Specialised services

Explained in: Complaining to your ICB: provider or commissioner?

Standard of care

Explained in: What is clinical negligence?Breach of duty in clinical negligence

Stay of proceedings

Explained in: Clinical negligence time limitsHow a clinical negligence claim works

Stocktake

Explained in: How a clinical negligence claim works

Subject access request

A request exercising the data-protection right of access to personal information held by an organisation. A living patient can use this route to request personal health information from organisations that hold it.

Read more: Getting your medical records

T

Third-party information: Explained in: Getting your medical records
Trial: Explained in: How a clinical negligence claim works

U

UK GDPR: Explained in: Getting your medical records

W

Williams v The Bermuda Hospitals Board: Explained in: Causation in clinical negligence
Wilsher: Explained in: Causation in clinical negligence
Witness statement: Explained in: How a clinical negligence claim works