Clinical negligence claims can appear complex, particularly for individuals who have not previously engaged with the legal system. This simple blog is intended to explain, in clear and accessible terms, the legal criteria that must be satisfied before a clinical negligence claim can succeed under English law.

In short, it is not enough that something went wrong during medical treatment. 

The law requires a claimant to prove several distinct elements. If any one of these elements cannot be established, a claim is unlikely to succeed.

Duty of Care

The first requirement is that the healthcare professional or organisation owed the patient a ‘duty of care’.

In practice, this is rarely contentious. Doctors, nurses, dentists, midwives, physiotherapists and hospitals (including NHS Trusts and private providers) owe a duty of care to their patients as soon as a professional relationship is established. This applies to diagnosis, treatment, aftercare and, in some circumstances, advice given remotely.

Once a duty of care is established, the focus moves to the standard of the care provided.

Breach of duty

To succeed in a clinical negligence claim, it must be shown that the healthcare provider ‘breached’ their duty of care.

This means demonstrating that the treatment fell below an acceptable reasonable standard. Importantly, the law does not require treatment to be perfect, nor does it penalise all errors. The test is whether the clinician’s actions were supported by a responsible body of medical opinion at the relevant time. This is often referred to as the Bolam test. 

Moreover, even if a responsible body of medical opinion would support the treatment or decision made, the Court must still be satisfied that such opinion is logical, reasonable and defensible. This additional safeguard is known as the Bolitho test and allows the Court to reject expert evidence where it considers that opinion to be irrational or incapable of withstanding logical analysis.

Examples of a potential breach of duty include:

• A failure to diagnose or a delayed diagnosis where symptoms were clear or where appropriate tests were not arranged
• Misdiagnosis leading to incorrect or delayed treatment
• Surgical errors, including operating on the wrong site, retained surgical instruments or avoidable damage to surrounding structures
• Prescribing the wrong medication, the wrong dosage, or failing to identify known drug allergies or interactions
• A failure to obtain informed consent, including not warning a patient of material risks or reasonable alternative treatments
• Inadequate monitoring during treatment, labour or recovery, including a failure to recognise signs of deterioration
• Poor follow‑up care or failure to act on abnormal test results
• Delays in referral to an appropriate specialist
• Failures in record keeping, communication or handover between clinicians

We advise on and pursue most types of clinical negligence claims. The most common categories include failures in diagnosis, surgical negligence, medication errors, negligent hospital and GP care, errors in emergency and urgent care, and failures in mental health treatment.

Birth injury claims are a significant and important area of clinical negligence. These cases may arise from negligent antenatal care, failures to appropriately monitor mother or baby during labour, delayed or inappropriate intervention during delivery, or inadequate neonatal care after birth. Such failures can result in serious and life‑changing injuries, including brain injury, cerebral palsy, brachial plexus injuries and stillbirth or neonatal death.

Whether care falls below an acceptable standard will always depend on the specific facts of the case, the medical context at the relevant time, and the available expert evidence.

Causation

Establishing a breach of duty is not sufficient on its own. The claimant must also prove causation.

Causation addresses the question of whether the injury or harm would have been avoided ‘but for’ the negligent care. In simple terms, this means asking whether the damage would still have occurred if appropriate care had been provided. Even where care is proven to be substandard, a claim will fail if the same outcome would have occurred in any event.

This is often the most complex and contested aspect of a clinical negligence claim. By way of example:

• A delayed diagnosis may not amount to a successful claim if earlier diagnosis and treatment would not have changed the course or outcome of the condition

• A surgical error may not be actionable if it did not cause any additional injury or worsen the patient’s condition

In some cases, however, the law recognises that medical outcomes are not always attributable to a single cause. Where an injury has resulted from a combination of factors, including negligent care, the Court may apply the ‘material contribution test’. Under this test, it is not necessary for the claimant to prove that negligence was the sole cause of the injury. Instead, it must be shown that the negligent care made a material, more than negligible, contribution to the harm suffered.

This approach is commonly encountered in cases involving complex medical histories, multiple potential causes of injury, or cumulative damage over time, such as in certain orthopaedic, respiratory or birth injury cases.

Causation, whether assessed on a ‘but for’ basis or by applying the ‘material contribution test’, must be supported by clear and persuasive expert medical evidence. Expert opinion is required to address both what would have happened with appropriate care and whether the negligence made a meaningful difference to the outcome.

Injury, harm or loss

A claimant must have suffered an injury, harm or loss as a result of the negligence.

This can include physical injury, worsening of an existing condition, psychological injury, or in fatal cases, death. Financial losses may also be claimed, such as loss of earnings, care costs, treatment expenses and adaptation costs.

Minor or trivial injuries are unlikely to justify a clinical negligence claim, particularly once the costs and risks of litigation are taken into account.

Limitation periods

Clinical negligence claims are subject to strict time limits.

In most cases, court proceedings must be issued within three years of the date of the negligent treatment, or three years from the date when the claimant first became aware that the injury may have been caused by negligent care. This is known as the date of knowledge.

Different rules apply for:

• Children, where time generally runs from their 18th birthday
• Individuals lacking mental capacity, where time may not run at all
• Fatal cases, where time usually runs from the date of death or date of knowledge of the dependants

If proceedings are not issued within the applicable limitation period, the claim is likely to be barred, regardless of its merits.

What clinical negligence is not

It is important to understand that not every poor outcome or complication gives rise to a claim.

Medical treatment carries inherent risks, and some conditions progress despite appropriate care. A claim will not succeed simply because treatment was unsuccessful, provided it met the appropriate standard and the risks were properly explained.

Similarly, a difference of professional opinion does not automatically amount to negligence.

Evidence and investigation

Clinical negligence claims require detailed investigation. This typically involves:

• Obtaining and reviewing medical records
• Taking witness statements
• Instructing independent medical experts
• Considering legal and medical causation together

Given the complexity of these cases, early specialist advice is strongly recommended.

Conclusion

To summarise, a successful clinical negligence claim requires proof of:

• A duty of care
• A breach of that duty
• A causal link between the breach and the injury
• Actual injury, harm or loss

Each element must be supported by appropriate evidence. If you believe you may have suffered harm as a result of substandard medical care, a specialist clinical negligence solicitor can advise on whether these criteria are likely to be met and guide you through the process.