Almost everyone has had one - the boss who cancels your one-to-one three weeks running, the micromanager who rewrites your emails before they go out, the credit-taker who presents your idea in the leadership meeting as their own. A difficult manager will not usually change because you wish they would. What changes your situation is how you read them and how carefully you protect yourself, and both of those are skills you can learn.
Work out which type you are dealing with
Difficult bosses are not all the same, and the wrong response makes the wrong one worse. The micromanager is often anxious rather than malicious, and the fix is to over-communicate progress so they feel informed enough to let go. The absent manager leaves you starved of direction, so you bring them tightly framed decisions rather than open questions. The credit-taker needs a paper trail. And the genuinely hostile manager - the one who belittles you in front of others or moves the goalposts to set you up to fail - is a different category altogether, and you should stop trying to manage that one alone. Naming the type tells you which lever to pull.
Document everything, calmly
This is not paranoia; it is professional hygiene. Keep a dated record of instructions, decisions and any incident that felt off, and follow up verbal conversations with a short email - "Just to confirm what we agreed..." - so there is a written version of reality that does not depend on memory. I once watched a colleague save her own job with nothing more than a folder of timestamped emails when her manager claimed she had never been briefed. The record does not need to be elaborate; a dated note in a private document the same day is enough, and it protects you precisely because it was written before anyone knew it would matter. Be specific, stick to facts, and leave the adjectives out.
When to escalate
If the behaviour crosses into bullying, discrimination or anything that breaches the Equality Act 2010, raise it - first informally if you can, then formally through HR's grievance procedure. Read your staff handbook so you know the exact process before you start, because following it properly matters. ACAS offers free, confidential advice on workplace conflict and can tell you whether your situation has crossed a legal line. You do not owe a bad manager your silence, and staying quiet rarely makes it stop.