Almost every organization has an office pest. He/she talks incessantly. Sings. Makes popping noises. Drums on his desk. Comes into your office or cubicle, plops down and starts complaining and whining. Brings food into the cubicle next to you, eats sloppily while talking loudly with friends on the phone. Stops by to criticize your work, appearance, décor or behavior every hour or so. Cooks stinky food in the office microwave. Plays practical jokes.
Whatever it is that your particular pest does, it's unacceptable behavior for a work environment (maybe for any environment.) It's affecting your ability to do your job and you want it to stop. Here are the usual ways other folks have successfully dealt with it.
1. Talk to him/her. Don't wait until you're ready to explode. This is the first thing you should try. Every organization will expect you to do your best to work out your differences with other employees. It's considered part of everyone's job skills. If you're having trouble with another employee, the general management response will be to ask you what you did to try to resolve your issues.
Ask around and find out if anyone else has the same problem and if they've resolved it. If not, take a while to think about what you want the pest to do and why it's necessary. Then plan how to ask for what you want tactfully. Think about what is the ideal change and what is the minimum acceptable change. You are preparing for a negotiation. You likely won't get everything you want. But you will get as much as you can. If you don't know how to negotiate, read up on it. There are plenty of free articles online and many, many good books. (See recommendations below.)
It's well worthwhile to take this as an opportunity to learn negotiation skills. You need them all your life.
Pick a time when you feel like you can negotiate rationally (especially important when dealing with someone else who isn't very rational). Make it as impersonal as possible to them and as personal as possible to you. "When you sing (or talk to your girlfriend loudly) while I'm doing math, I can't concentrate. I'm going to put this little white flag on my desk when I need to focus. Can you agree to keep it down when you see the flag.
Remember to take it one behavior at a time. "Kitchen sink" approaches to resolving all the complaints at once just engender resentment and get nowhere.
2. Talk to your boss. If your office mate's bad behavior is affecting your productivity, your boss should be concerned. And it's his or her job to discipline the culprit. If your boss doesn't help and there's a system in your organization for handling this through H.R., by all means pursue it. If your work suffers, you'll be the one getting bad performance reviews.
3. Get headphones. If it's noise or too much talk that bothers you, get some headphones or earbuds and play white noise. Even better, play music that calms.
4. Take lots of breaks. Get away from the environment at least once per hour. Maybe even every half-hour. Make it a working break. Go do some photocopying for 5 or 10 minutes. Hand deliver a memo. Check with a colleague on some research.
5. Find other temporary work locations. If your organization has a library or unoccupied offices or cubicles, take some work to a pest-free environment for a while. Accidentally leave your cell phone off. Forget to tell anyone where you'll be. But come back with an armful of finished work.
The real solution to the problem is with management. Because, chances are that the pest is a pest to everyone, not just you. So, it may well be that management already is aware of the problem and has done nothing about it. If you've unsuccessfully tried to resolve your issues with the pest and management won't do anything, you don't have many options. You'll have to get another job -- within the organization or elsewhere.
In the long run, crazy-making office mates do end up making you crazy. Get out while you're sane.