The most common type of workplace violence is client-on-worker violence, classified as Type 2 in the standard framework used by the National Institute for Occupational Safety and Health (NIOSH). This category covers incidents where a customer, patient, visitor, or anyone receiving services becomes aggressive toward an employee. It is especially dominant in healthcare, where the injury rate from intentional harm by another person is five times higher than the average across all private industries.
The Four Types of Workplace Violence
NIOSH classifies workplace violence into four categories based on the relationship between the aggressor and the worker. Understanding which type you’re dealing with matters because each one has different warning signs, different risk factors, and different prevention strategies.
- Type 1, Criminal Intent: The perpetrator has no legitimate connection to the business. These incidents typically involve robbery, shoplifting, or trespassing and account for most workplace homicides.
- Type 2, Client-on-Worker: The aggressor is a customer, patient, family member, or visitor. This is the most common form overall, particularly in healthcare and service industries.
- Type 3, Worker-on-Worker: Sometimes called lateral or horizontal violence, this includes bullying, verbal abuse, intimidation, and in rare cases physical assault between coworkers. It often flows downward in a hierarchy: supervisor to employee, doctor to nurse.
- Type 4, Personal Relationship: The perpetrator has a personal relationship with the employee (such as a domestic partner) that spills into the workplace.
Why Client-on-Worker Violence Is the Most Common
Any job where employees regularly interact with the public carries some risk, but healthcare and social assistance stand out dramatically. In 2018, workers in those fields experienced nonfatal injuries from intentional harm at a rate of 10.4 per 10,000 full-time workers, compared to just 2.1 per 10,000 across all private industries. That gap reflects the sheer volume of high-stress, emotionally charged interactions that nurses, social workers, emergency department staff, and home health aides face every shift.
Patients with dementia or disorientation, people in acute psychiatric distress, and family members overwhelmed by a medical crisis are all common sources of Type 2 incidents. The aggression is not always calculated. Much of it stems from confusion, fear, pain, or substance use, which makes it harder to predict and harder to prevent.
Outside of healthcare, retail workers, public transit operators, and educators also face frequent Type 2 violence. Anywhere a worker stands between a frustrated person and something they want (a refund, a service, a decision), the potential for aggression rises.
Verbal Aggression Far Outpaces Physical Violence
When people picture workplace violence, they often think of physical attacks. But verbal aggression, including threats, insults, and intimidation, is far more common. A large meta-analysis of healthcare workers found that about 63% had experienced verbal violence during their careers, compared to 17% who had experienced physical violence. Looking at just the previous year, roughly 60% reported verbal aggression and 19% reported physical assault.
This three-to-one ratio holds across most research on the subject. Verbal abuse may not leave visible injuries, but it drives burnout, anxiety, turnover, and long-term psychological harm. It also tends to escalate. Environments where verbal aggression is tolerated or dismissed as “part of the job” see higher rates of physical violence over time.
Worker-on-Worker Violence Is Harder to Spot
Type 3 violence between coworkers rarely makes headlines unless it escalates to something extreme. Day to day, it looks like bullying, public humiliation, sabotaging someone’s work, or persistent hostility. NIOSH describes it as “verbal and emotional abuse that is unfair, offensive, vindictive, and/or humiliating.” It spans a spectrum from snide comments to physical confrontation.
This type of violence tends to follow power dynamics. It is often directed at people perceived as lower in the hierarchy. In nursing, for example, experienced nurses targeting newer staff is well documented enough to have its own shorthand: “nurses eat their young.” Peer-to-peer aggression is also common, especially in high-pressure environments where competition for shifts, assignments, or recognition runs high.
Because it rarely involves a single dramatic incident, worker-on-worker violence is easy to dismiss. Many organizations treat it as a personality conflict rather than a safety issue, which means it persists longer and causes more cumulative damage than a single physical altercation might.
Workplace Homicides Tell a Different Story
Fatal workplace violence follows a different pattern than nonfatal incidents. In 2024, there were 470 workplace homicides in the United States, accounting for 64% of all fatal violent acts at work. Many of these deaths fall under Type 1 (criminal intent), involving robberies or other crimes where the perpetrator has no relationship to the business.
Protective service workers, including law enforcement, accounted for 97 of those homicides. Women made up 8.1% of all workplace fatalities but 15.3% of workplace homicide victims, a disproportion partly linked to Type 4 violence, where domestic abuse follows a victim to work.
So while Type 2 violence generates the highest total number of incidents, Type 1 violence is disproportionately lethal. This distinction matters for prevention: the strategies that reduce patient aggression in an emergency room are completely different from those that protect a convenience store clerk during a late-night robbery.
Most Incidents Are Never Reported
The numbers cited above almost certainly undercount the problem. Research on healthcare workers found underreporting rates as high as 80% to 90% in some settings. One prospective study found that the ratio of observed incidents to expected incidents was as low as 0.27, meaning roughly three out of four violent events went unreported.
Workers skip reporting for several reasons. Some believe aggression is just part of the job, especially in healthcare or social services. Others worry about retaliation, doubt that reporting will change anything, or don’t realize that verbal threats qualify as reportable incidents. In settings where patients are confused or mentally ill, staff sometimes feel that reporting an assault is unfair to someone who “didn’t mean it.”
This underreporting creates a cycle. When incidents go unrecorded, employers underestimate the problem, invest less in prevention, and the culture of acceptance deepens. Organizations that have implemented systematic violence monitoring, tracking every incident regardless of severity, have seen their reporting rates climb substantially, giving them the data they need to intervene before a pattern escalates.
The Scale of the Problem
Over the 2023 to 2024 period, the Bureau of Labor Statistics recorded roughly 54,500 cases of nonfatal workplace violence in private industry that resulted in days away from work, plus another 23,800 cases that led to job transfer or restricted duties. Combined, that is more than 78,000 incidents serious enough to affect someone’s ability to do their job, just in the private sector and just among the fraction that gets reported.
Those numbers represent real costs: lost wages, medical bills, workers’ compensation claims, and the quieter toll of employees who leave a profession entirely because they no longer feel safe. For the individual worker, understanding which type of violence is most relevant to your industry helps you recognize early warning signs and push for the specific protections that actually reduce risk in your setting.