Most advice about difficult coworkers assumes you need to fix the relationship. Usually you just need to manage it well enough that it stops draining you every day.
Before doing anything else, it's worth getting specific about what kind of difficult you're actually dealing with, because the right response is different for each. Someone who's abrasive but genuinely reliable and honest is a different problem than someone who's pleasant but unreliable, and both are different from someone who's actively undermining you. Treating all three the same way, usually with the same polite avoidance, tends to leave the real problem unaddressed.
For someone who's just blunt or short in a way that reads as difficult but isn't actually malicious, the most effective move is often the simplest: adjust how you deliver things to them without changing what you expect back. Some people are difficult because their communication style clashes with yours, not because their character is the problem. Meeting them with less small talk and more direct requests can dissolve friction that felt personal but wasn't.
Instead of a long, context-heavy message to someone known for terse replies: "Need your sign-off on the budget by Thursday. Two line items flagged in yellow, everything else is unchanged from last quarter." Matching their style often gets you a faster, warmer response than trying to draw them into yours.
For someone whose difficulty is really about unreliability or inconsistency, saying one thing and doing another, skip the personality lecture and fix the structure instead. Put agreements in writing after conversations, confirm deadlines explicitly, and don't rely on memory of a verbal commitment when the pattern suggests it won't hold. You've already seen the pattern, protect the work accordingly.
The hardest category is someone who's genuinely working against you, taking credit that isn't theirs, undermining you to others, or being inconsistent specifically when it benefits them. Here, the instinct to avoid conflict tends to make things worse over time, not better. Naming the specific behavior directly, calmly, and in private is usually more effective than either confronting it publicly or quietly absorbing it. "I noticed the client presentation credited you for the analysis I put together, can you help me understand what happened there?" opens a real conversation instead of letting resentment build silently.
Peer conflict is harder. There's no formal structure underneath it, nobody has to listen to you, just two people who have to keep working together with no one clearly in charge of fixing it.
Avoidance doesn't make it fade, it calcifies into a low-grade tension you both quietly manage around for months. Name it directly instead, and frame the specific behavior, not the person's character, so it stays something fixable rather than something personal.
"I wanted to talk directly rather than let this sit. I've noticed our last couple of handoffs have had some miscommunication, and I think it's created some tension between us. Can we figure out a better way to hand things off, so we're not stepping on each other?"
Directness without warmth just bounces off. Say the specific thing, but say it like you're actually trying to fix it together, not win the exchange.
Not every difficult relationship resolves into a good one, and that's fine. You're not aiming for friendship, with a report or a peer. The goal is a working relationship stable enough that the friction stops draining energy that belongs somewhere else. Some people you'll never fully warm to, and you can still work with them well.