A pre-existing medical condition does not automatically disqualify an employee from claiming a workplace accident in Spain, according to labor law specialists.
Article 156 of the General Social Security Law covers prior conditions that are aggravated as a consequence of a workplace incident. The legislation presumes that injuries sustained during working hours and at the workplace are occupational unless proven otherwise, meaning the mere existence of a prior injury is not enough to dismiss the professional origin of a claim.
Workplace conditions can trigger damage, aggravate an existing issue, or cause previous symptoms to reappear.

The classification of an injury dictates who provides medical care, which entity is financially responsible, and how temporary disability benefits are managed. Temporary disability provides financial support to employees who are medically unfit to work.
A mutual insurance company's initial response does not finalize how an injury is classified. In Spain, mutual companies collaborate with the Social Security system to manage occupational risks on behalf of employers. The TikTok account Realidad Laboral noted that workers are often discouraged from pursuing claims by phrases attributing injuries to age or prior conditions, but they can still challenge a mutual company's decision.
If a mutual company assesses an injury and classifies it as a common condition rather than an occupational one, it may refer the worker to the public health system. Social Security requires the mutual company to issue an assistance report when making this referral.
Documenting the Incident
Realidad Laboral advised workers to request the assistance report before leaving the medical center, as seeking initial care at the mutual company establishes medical evidence from the outset. These first documents can shape the course of a subsequent claim.
The assistance report must detail the pathology, the diagnosis, the tests conducted, the treatment prescribed, and the specific reasons for classifying the ailment as a common condition. This documentation shows what decision was made and why.
Medical leave is granted based on a clinical assessment by an examining doctor, rather than a patient's mere request. If the injury prevents the employee from working, they must seek a medical evaluation.
For common conditions, the public health service handles the assessment and issues the medical report. For businesses that protect their professional contingencies with a mutual company, that entity's medical services handle the initial assessment.
Appealing a Classification
If the public system issues standard medical leave following a referral from a mutual company, the worker can formally petition the National Institute of Social Security to determine the contingency. The agency is Spain's state body responsible for managing public healthcare and social benefits.
The determination procedure relies on the initial assistance report and any available medical tests. The agency decides whether the origin of the injury is common or professional, whether a relapse has occurred, and which entity is responsible for providing benefits.
If the agency rules that the injury is work-related, the mutual insurance company is obligated to pay any corresponding favorable difference in compensation to the worker. The final decision is based on the worker's comprehensive medical and occupational history, rather than an isolated phrase.
Filing Complaints at Private Centers
In the Community of Madrid, workers treated at private health centers who disagree with an injury's classification are advised to use the official complaint form provided by the center. The regional Administration instructs that one copy of the form is delivered there and another is kept by the interested party.
The form should be used to detail the task being performed, the time and manner of the accident, the affected area, and the worker's disagreement with the classification. Workers should also retain any related prevention documents, communications, and medical reports if they exist.
While filing this complaint leaves a written record of what happened, it does not replace the formal petition process before the National Institute of Social Security.
Recent cases highlight the scope of occupational protections in Spain. A 42-year-old woman earning a monthly salary of 2,280 euros will receive 54,145 euros in compensation after fracturing her humerus at her workplace.
The Supreme Court also confirmed that a fatal heart attack suffered by a woman while teleworking constituted a workplace accident. Her family will receive the same financial compensation as the family of an on-site employee.

