Delayed Diagnosis Claims — Medical Negligence Compensation
Last reviewed: June 2026 · EA Personal Injury Solicitors
A delayed or missed diagnosis can allow a serious condition to progress when earlier treatment could have prevented or reduced harm. EA Personal Injury Solicitors handles delayed diagnosis negligence claims on a no win, no fee basis — if the claim succeeds, a success fee may be deducted from your compensation.
TL;DR — Quick Summary
Key Points
- Both failure to diagnose and undue delay in diagnosis can constitute negligence
- Causation — showing the delay made a material difference to outcome — must be proved
- "Lost chance" claims are possible even where cure was not guaranteed with earlier diagnosis
- Three-year limitation from date of knowledge of the missed diagnostic opportunity
- No win, no fee — if the claim succeeds, a success fee may be deducted from your compensation
Delayed Diagnosis as Clinical Negligence
A delayed or missed diagnosis can be just as harmful as a positive act of negligence. Where a clinician fails to consider a diagnosis that a reasonably competent practitioner in their position would have considered, fails to investigate, misinterprets test results or imaging, or fails to follow up, and the resulting delay causes the patient to suffer harm they would not have suffered had the diagnosis been made in time, a clinical negligence claim may succeed.
The two elements that must both be established are, as always in clinical negligence: (1) breach of duty — the diagnostic failure fell below the standard of a reasonably competent clinician in the relevant specialty; and (2) causation — the delay caused harm that would not have occurred, or would have been reduced, with a timely diagnosis.
Delayed Cancer Diagnosis Claims
Cancer claims represent the largest category of delayed diagnosis cases. Common scenarios include:
- GP failing to refer with symptoms meeting the criteria for an urgent two-week wait cancer referral
- Radiologist misreporting a scan or X-ray that showed features of cancer
- Pathologist misreporting a biopsy as benign when it was in fact malignant
- Breast cancer not detected on screening or symptomatic mammography
- Colonoscopy failing to identify a polyp or tumour present at the time of the procedure
- Prostate cancer signs (PSA elevation, symptoms) not followed up appropriately
In cancer cases, the causation analysis requires oncological expert evidence on what stage the cancer was at the time it should have been diagnosed, what treatment would have been given, and what the outcome would have been compared with the actual outcome following the delayed diagnosis.
Other Delayed Diagnosis Claims
- Sepsis — failure to recognise the clinical signs of sepsis and initiate the sepsis six pathway promptly
- Meningitis — dismissal of symptoms as viral illness; failure to recognise meningococcal disease
- Deep vein thrombosis and pulmonary embolism — failure to investigate leg swelling or breathlessness leading to fatal PE
- Fractures — failure to X-ray leading to missed fracture and delayed treatment
- Appendicitis — sending home with symptoms of appendicitis that went on to perforate
- Testicular torsion — delayed diagnosis causing avoidable loss of testis
No Win, No Fee Delayed Diagnosis Claims
We act under a Conditional Fee Agreement. If the claim fails, you pay nothing. If the claim succeeds, a success fee may be deducted from your compensation.