What Is Medical Negligence?

The Legal Definition of Medical Negligence

Medical negligence — formally termed clinical negligence — is a subset of the law of negligence as it applies to healthcare. To establish a successful claim, three elements must all be proven on the balance of probabilities:

1. Duty of care — the defendant healthcare professional or organisation owed you a legal duty of care.
2. Breach of duty — the defendant breached that duty by providing care that fell below the required standard.
3. Causation — the breach directly caused, or materially contributed to, the harm you suffered.

If any one of these three elements cannot be established, the claim will fail. Each element has its own legal tests, which are explained in detail below.

Duty of Care in Medical Negligence

A duty of care arises automatically in a clinical relationship. The moment a healthcare professional undertakes to treat, examine, or advise a patient, a duty of care exists. This applies to:

• NHS consultants, surgeons, anaesthetists, and junior doctors
• General practitioners and practice nurses
• Midwives, health visitors, and district nurses
• Private hospital clinicians and surgeons
• Dentists, optometrists, and other registered healthcare professionals
• NHS trusts and private healthcare organisations as corporate entities

The duty is personal and non-delegable. A trust cannot escape liability by arguing that the negligent clinician was exercising independent professional judgment — if the clinician was acting within the scope of their employment, the trust is vicariously liable.

The Bolam Test: The Standard of Care

The standard of care in medical negligence cases in England and Wales is assessed using the Bolam test, established in Bolam v Friern Hospital Management Committee [1957] 1 WLR 582. The test asks: did the defendant act in accordance with a practice accepted as proper by a responsible body of medical practitioners skilled in that particular art?

This means a doctor is not negligent merely because another doctor would have acted differently, or because the claimant's expert witnesses disagree with the approach taken. If the defendant can point to a responsible body of medical opinion that supports the treatment given, the Bolam test may be satisfied.

The Bolam test applies to:

• Diagnosis
• Treatment decisions
• Advice and consent
• Post-operative management
• Any other clinical decision-making

The Bolitho Refinement

The Bolam test was refined by the House of Lords in Bolitho v City and Hackney Health Authority [1997] UKHL 46. The court held that a body of medical opinion will only satisfy the Bolam test if it is capable of withstanding logical analysis. A judge is entitled to reject expert evidence that is not based on a defensible clinical rationale, even if that expert is eminent.

In practice, Bolitho challenges succeed relatively rarely — courts are cautious about substituting judicial opinion for genuine expert clinical disagreement. However, Bolitho has proved significant in cases where the defence relies on an outlying or minority clinical practice that cannot be rationally justified.

Causation: The But-For Test

Establishing that a duty was breached is not enough. The claimant must also prove that the breach caused the harm suffered. The primary causation test in English law is the but-for test: but for the defendant's breach of duty, would the claimant have suffered the harm?

If the harm would have occurred regardless of the breach — for example, because the patient's underlying condition would have produced the same outcome even with correct treatment — the causation element fails and the claim cannot succeed.

Material contribution

Where it is impossible to apply the strict but-for test — typically in cases involving divisible injuries or multiple contributing causes — the courts may apply the material contribution to harm or material contribution to risk doctrine, established in cases including Bonnington Castings Ltd v Wardlaw [1956] and Fairchild v Glenhaven Funeral Services [2002].

Loss of chance

English law does not generally permit recovery for loss of a less-than-even chance of a better outcome (Gregg v Scott [2005] UKHL 2). This is a significant limitation in delayed diagnosis cases where the question is statistical — for example, whether earlier diagnosis of cancer would, on the balance of probabilities, have produced a better outcome.

What Does Not Qualify as Medical Negligence

A number of situations are commonly misunderstood as potential negligence claims but do not meet the legal threshold:

Unsuccessful treatment with correct care

If your surgeon performed an operation in accordance with accepted technique and the operation failed to achieve the desired result, that is not negligence. Surgical risk is inherent; consent to surgery is consent to that risk.

Honest diagnostic error within accepted practice

Medicine involves uncertainty. A clinician who reaches an incorrect diagnosis having followed a reasonable diagnostic pathway — taking a proper history, examining the patient, ordering appropriate investigations, and applying defensible clinical reasoning — has not been negligent. The diagnosis must have been one that a responsible body of practitioners could reasonably have reached at the time.

Dissatisfaction with bedside manner

Rudeness, poor communication, or unsympathetic treatment, while potentially subject to formal complaints, does not constitute negligence unless it caused measurable clinical harm.

Known side effects of treatment

If you experienced a documented side effect of a prescribed medication or procedure, and that side effect was within the range of known risks disclosed during the consent process, there is no breach of duty.

NHS waiting times

Delayed treatment resulting from systemic NHS resource constraints, rather than an individual clinician's failure, does not generally give rise to a negligence claim, though it may support a complaint through the NHS complaints procedure.

Medical Negligence vs Adverse Outcome

This is perhaps the most important distinction for anyone considering a claim. An adverse outcome — a complication, a failed operation, a worsened condition — does not by itself indicate negligence. The question is always whether the care provided met the required standard, not whether the outcome was good or bad.

Experienced medical negligence solicitors assess cases by obtaining medical records, instructing independent expert witnesses in the relevant specialty, and obtaining a preliminary expert opinion on breach of duty and causation before any formal claim is pursued. The strength of independent expert evidence is what determines whether a case is viable.

If you are uncertain whether your experience amounts to negligence, the appropriate first step is to obtain your medical records and seek an independent legal opinion. A reputable specialist firm will assess the matter honestly, including advising you if the evidence does not support a claim.

Scotland and Northern Ireland

Scotland

Scottish medical negligence law applies the same basic standard — negligence requires a breach of the duty of care that causes harm — but through Scots law procedure. Claims are raised in the Court of Session (for larger claims) or the Sheriff Court. The limitation period is three years (the triennale) under the Prescription and Limitation (Scotland) Act 1973, with equivalent date-of-knowledge provisions.

Scots law developed its own approach to the standard of care independently of the English courts. While the outcome is broadly similar to the Bolam standard, Scottish judges have emphasised that the focus is on whether the specific decision was reasonable, rather than whether a body of practitioners would have done the same thing.

The equivalent of NHS Resolution in Scotland is the Central Legal Office, which handles claims against NHS Scotland boards.

Northern Ireland

Medical negligence in Northern Ireland is governed by the same substantive legal principles as England and Wales, with the Bolam test applying directly. Claims are brought in the High Court of Justice in Northern Ireland. The relevant defendants for claims against the public health system are the Health and Social Care trusts. The limitation period is three years under the Limitation (Northern Ireland) Order 1989.

Examples of Medical Negligence

The following are illustrative categories of clinical error that may give rise to a negligence claim. These are examples only and should not be taken as an indication that any specific situation will or will not meet the legal threshold:

• A surgeon operates on the wrong site or wrong patient due to inadequate pre-operative checks
• A GP repeatedly fails to refer a patient with symptoms consistent with cancer, resulting in diagnosis at a significantly advanced stage
• An anaesthetist administers an incorrect dose, causing awareness during surgery or post-operative complications
• A midwife fails to act on foetal monitoring evidence of distress, resulting in hypoxic injury to the child
• A hospital pharmacist dispenses the wrong medication to a patient with a known contraindication
• A radiologist misreads an imaging result, causing a diagnosis to be missed for a period in which the condition progresses

Next Steps

If you believe you or a family member may have been the victim of medical negligence, the following steps will help you understand and protect your legal position:

1. Obtain your medical records

You are entitled under data protection law to request all records held about you by any NHS or private healthcare provider. Your solicitor can assist with this.

2. Note the dates

The three-year limitation period means timing matters. Note when the treatment occurred and when you first became aware something may have gone wrong.

3. Seek specialist legal advice

Medical negligence is a highly specialist area of law. A general personal injury firm is not the same as a specialist clinical negligence practice. Look for solicitors regulated by the Solicitors Regulation Authority (England and Wales), the Law Society of Scotland, or the Law Society of Northern Ireland, with a demonstrable track record in clinical negligence.

4. Do not complain to the NHS first as a substitute for legal advice

The NHS complaints procedure and a legal claim are separate processes. Making a complaint does not start or stop the limitation period, and the two processes can run in parallel. However, a legal adviser should be consulted before any written communications that might affect your legal position.

Continue Learning

• Glossary of medical negligence terms — Bolam, Bolitho, Montgomery and more
• Medical negligence FAQ — common questions answered
• All types of medical negligence claim