Certain behaviors signal more than just a bad day—they point to deeper instability that needs attention.
Every workplace has tough days, stressed-out employees, and occasional drama. But sometimes, certain patterns start to show up that go way beyond normal work stress. When someone’s behavior starts to feel unpredictable, disruptive, or even a little concerning, it may be a sign they’re struggling with deeper personal or mental health issues that affect not only their own well-being but also the team’s stability.
Recognizing these signs isn’t about labeling people or creating office gossip—it’s about knowing when a situation has moved into territory where real support or intervention might be needed. Whether you’re a manager, a coworker, or simply someone who’s observing changes, these 11 signs of an unstable employee can help you identify when it’s time to step in or seek professional help to protect both the person and the workplace as a whole.
1. They have extreme mood swings that shift without warning.
Everyone has ups and downs, but when someone goes from cheerful to irritable or completely withdrawn within hours—or even minutes—it becomes hard for coworkers to predict how to interact with them, according to Kailash Ganesh at Culture Monkey. These sudden emotional shifts create tension and confusion within teams.
Frequent mood swings can be exhausting for both the person experiencing them and those around them. If these patterns persist, they may signal underlying mental health issues such as anxiety, depression, or mood disorders. Addressing it early with support or professional help may prevent things from escalating further.
2. They frequently overreact to small issues or criticism.
Constructive feedback or minor setbacks shouldn’t trigger emotional outbursts or disproportionate responses. An unstable employee may take even the smallest correction as a personal attack, leading to tears, anger, or complete shutdowns over routine conversations, as reported by Kristen Fuller at Discovery Mood.
These reactions create a stressful environment for both managers and peers, who may start walking on eggshells to avoid triggering another meltdown. This inability to regulate emotions often indicates that deeper stress or psychological issues are at play, requiring sensitivity and possibly HR involvement to ensure proper support.
3. They constantly miss deadlines or forget basic responsibilities.
Occasional forgetfulness happens to everyone, but an unstable employee may struggle to complete even simple tasks reliably, as stated by the authors at Teramind. Deadlines slip repeatedly, assignments are incomplete, or they forget instructions entirely, creating a noticeable pattern of unreliability.
This kind of cognitive disorganization could point to burnout, anxiety, or other personal struggles that interfere with focus and memory. When performance deteriorates consistently, it’s often a sign that the person needs more than just a productivity pep talk—they may need professional assistance or a supportive work adjustment.
4. They isolate themselves and avoid team interaction.
While some people are naturally introverted, sudden or increasing social withdrawal can indicate something deeper. An employee who avoids meetings, skips team lunches, or physically distances themselves from coworkers may be struggling emotionally or mentally.
Isolation often signals feelings of overwhelm, depression, or anxiety that make even small social interactions feel draining. When this behavior becomes consistent, it may be time to gently check in and explore whether outside support could help address the root cause.
5. They create ongoing drama or conflicts with coworkers.
An unstable employee may struggle to maintain healthy workplace relationships, frequently clashing with others over minor disagreements. Gossip, passive-aggressive comments, or outright arguments become regular occurrences, creating tension across the team.
Constant conflict often reflects poor emotional regulation, paranoia, or feelings of being victimized. This not only disrupts productivity but can poison team morale if left unchecked. At this stage, management may need to intervene with both conflict resolution strategies and possibly recommend counseling resources.
6. They frequently call out sick or have mysterious absences.
Unexplained absences, last-minute sick days, or sudden disappearances during the workday may point to personal struggles spilling into the workplace. While occasional emergencies happen, a pattern of frequent absences suggests a bigger issue that’s interfering with stability.
These disappearances may be linked to medical appointments, mental health crises, or avoidance of workplace stress altogether. If attendance becomes unreliable and unpredictable, HR may need to step in to help the employee access appropriate support before their job security—and health—deteriorates further.
7. Their personal appearance or hygiene noticeably declines.
Changes in grooming, dress, or personal hygiene often signal that someone is struggling more deeply. An employee who once dressed professionally may start showing up disheveled, unkempt, or noticeably neglectful of their appearance.
While it’s important not to judge anyone harshly for how they look, noticeable declines in self-care can be a sign of depression, anxiety, or other serious personal issues. These changes often warrant a compassionate conversation to offer support and encourage seeking help.
8. They display paranoid behavior or constant suspicion of others.
When an employee regularly believes others are “out to get them,” questions everyone’s motives, or assumes harmless interactions are personal attacks, it can create a toxic atmosphere that spreads anxiety throughout the team.
This type of thinking may be a symptom of deeper psychological distress or paranoia. Left unchecked, it can escalate into serious HR concerns, damaging trust and team collaboration. Early intervention can prevent the employee’s mental health—and the workplace culture—from spiraling further.
9. They exhibit bursts of grandiosity or unrealistic confidence.
Sudden, extreme confidence where someone believes they can do anything, claim credit for others’ work, or dismiss valid feedback as irrelevant can be just as concerning as anxiety or withdrawal. These manic-like behaviors may feel thrilling to them but destabilizing for everyone else.
This extreme confidence can sometimes precede impulsive decisions that put projects or relationships at risk. While some confidence is healthy, when it crosses into delusion or arrogance, it may indicate underlying bipolar tendencies or other mental health conditions needing professional evaluation.
10. They talk openly about hopelessness or feeling trapped.
When an employee frequently mentions feeling stuck, hopeless, or unable to cope, these aren’t just casual complaints—they’re major red flags. Phrases like “I don’t know how much longer I can take this” or “What’s even the point anymore?” suggest deeper emotional pain.
These warning signs should never be ignored. HR or management may need to intervene quickly, not only to protect the employee’s well-being but to ensure the workplace remains safe and supportive for everyone involved.
11. Their performance fluctuates wildly without explanation.
One week they’re excelling, the next they’re barely functioning—it’s this unpredictability that creates serious concern. An unstable employee often swings between bursts of productivity and total disengagement with no clear external cause.
These wild shifts often signal underlying struggles with emotional regulation, untreated mental health conditions, or overwhelming personal crises. Consistent support, compassionate check-ins, and potentially connecting the employee with professional resources can help stabilize their work life and prevent long-term consequences for both the employee and the organization.