Every workplace has one.
Sometimes it's the person who cc's your manager on everything, for no reason, constantly. Sometimes it's the one who takes credit in meetings then pleads ignorance when things go wrong. Sometimes it's the one who's perfectly pleasant to your face and a completely different person the moment you leave the room.
You know the type. You might be sitting three desks away from one right now.
Toxic colleagues are one of the most under-discussed reasons people hate their jobs. Not the work itself. Not the commute. The specific human being who makes an already difficult situation significantly worse every single day.
This is about them.
First: what actually makes a colleague toxic.
Not annoying. Not irritating. Not someone who microwaves fish or talks too loud on calls or says "per my last email" like it's a personality trait.
Toxic is specific. A toxic colleague is someone whose behaviour consistently and deliberately makes your working life harder.
There are a few varieties.
The Credit Thief. Your idea goes into a meeting and comes out with someone else's name on it. You've watched it happen in slow motion. You've sat there while your manager nodded at them and thought: that was mine. I said that. Two weeks ago. In this room.
The Underminer. Everything they say about you is technically fine. Technically. "She's great, just takes a while to get up to speed." "He did a good job, considering." Plausible deniability wrapped in a compliment-shaped knife.
The Chaos Agent. They don't have to do anything overtly wrong. They just create instability. Rumours. Shifting alliances. A vague sense that everyone is slightly on edge whenever they're in the room. Drama finds them like a heat-seeking missile, and somehow you always end up standing nearby when it lands.
The Weaponised Incompetent. They can't do the thing. They've never been able to do the thing. Everyone knows they can't do the thing. But pointing it out somehow becomes your problem. Their failure becomes your workload. Their gaps become your emergency.
The Performative Martyr. Always busy. Always overwhelmed. Always the first to mention how late they stayed, how much they've taken on, how nobody understands the pressure they're under. Every conversation is a competition for suffering. You mention you're stretched thin. They mention they haven't slept in three days and are basically holding the company together with their bare hands.
You probably recognised at least two of those without having to think very hard.
Why toxic colleagues are so exhausting.
It's not just the behaviour itself. It's the mental real estate.
You spend the commute home replaying the meeting. You're in the shower working out what you should have said. You're at dinner, physically present, mentally composing the email you're not going to send. You're lying awake at 1am running through scenarios that haven't happened yet, pre-emptively losing arguments with someone who isn't even in the room.
That's the real damage. Not the thing they did. The thing they've made your brain do with it, on their behalf, in your own time.
A toxic colleague doesn't just ruin your working hours. They colonise the hours around them too.
What doesn't work.
People who operate like this have usually been operating like this for years, across multiple jobs, and nobody has stopped them yet. You are not going to be the person who fixes them with the right tone of voice in a Tuesday afternoon meeting.
Matching their energy. Going low with someone who operates below the line just means you're both below the line now. You've handed them exactly what they wanted: a version of you that looks like the problem.
Venting constantly. Necessary sometimes. Necessary in moderation. But if every conversation you have about work eventually circles back to this person, they've won something they don't even know they're competing for. Your narrative is now about them.
Waiting for HR to sort it. HR exists to protect the company. Sometimes that aligns with protecting you. Sometimes it doesn't. Go in clear-eyed about which situation you're in.
What actually works.
Document everything. Not in a paranoid way. In a practical, this-is-real way. Dates, times, what was said, who was there. Not because you're definitely going to war, but because memory is unreliable under stress and written records aren't. If it ever comes to a conversation with management, you want facts, not feelings. Feelings are easy to dismiss. A timestamped paper trail is considerably harder to wave away.
Stop performing normality. You don't have to be rude. But you can stop pretending everything is fine when it isn't. Cool, professional, and boundaried is a perfectly valid gear. You don't owe warmth to someone who is actively making your life harder.
Get clear on what you actually want. Do you want the behaviour to stop? Do you want it on record? Do you want to leave? These require different actions. Most people stay stuck because they haven't decided what outcome they're actually working toward. Pick one. Then work backwards from it.
Own your work loudly. Not aggressively. Just visibly. Send the follow-up email after the meeting. Put your name on the document. Loop in your manager on the progress before someone else gets the chance to summarise it for them. Credit thieves rely on your silence. Stop being silent.
There's a whole chapter on this in The Dead End Desk Survival Guide — the one people message about most. Because this is the thing that breaks people. Not the big dramatic moments. The slow, daily grind of sharing space with someone who makes everything slightly worse, every single day, indefinitely.
The thing nobody wants to hear.
Sometimes the toxic colleague isn't going anywhere. Sometimes they're protected. Sometimes they're the manager's favourite, or they've been there longest, or the politics of the place make them untouchable.
In that case, the question stops being "how do I fix this" and becomes "how long am I willing to stay in an environment where this is allowed to continue."
That's a harder question. But it's the honest one.
You cannot always control who you work with. You can control how much of your life you hand over to them. Your commute home is yours. Your evenings are yours. The inside of your head is yours.
One last thing.
If you're reading this and nodding along — and you've been nodding along for a while — pay attention to that. The fact that you've had to develop a detailed taxonomy of difficult colleagues, that you can identify their type on sight, that you know exactly which variety you're dealing with without having to think about it — that's not normal. That's what happens when you've been in a bad environment long enough that navigating it has become a skill.
You shouldn't need that skill. Not every day. Not like this.
The most exhausting thing about a toxic colleague isn't what they do at work. It's what they make you do with it afterwards, alone, in your own time.
