Working in a hostile environment is not only unhealthy, but can also be frightening for some people as well. There will always be co-workers that you do not necessarily get along with, but in workplace abuse, the line gets crossed when such co-workers start to invade your personal space, or begin spreading rumors or harassing you in other different ways. The best advice that can be given is to just ignore the situation, do the job and go home at the end of the day. However, when the harassment continues on a constant basis, it is time to stand up for yourself and try to put a stop to the abuse.
When you feel like the harassment is starting to get out of hand, try talking to your co-worker/s about it directly. Perhaps you said or did something that could have been misunderstood or misconstrued. Sometimes talking out your issues with your co-worker can be the end of the harassment. If talking with them does not work and the workplace abuse continues, the next step would be to consult with your supervisor or manager about the situation. Explain to them what has happened, giving exact examples of how you are being harassed or abused and be sure to tell them that you tried to go directly to them to no avail. At this point, you have done your part and it should be out of your hands and now at your supervisor's discretion to deal with your co-worker. Be prepared that they may just get written up and can continue on with their job. If the abuse is serious enough, it may call for immediate termination. Be prepared to suffer the backlash from other employees, especially if your co-worker was well liked.
Sometimes, it is just easier to transfer to another department within your company or to leave your company for another position altogether than deal with a workplace abuse situation. If you have a strong and determined personality, you may be able to stand firm against workplace harassers, but, if it is too emotionally draining for you to deal with the abuse on a constant basis, start fresh somewhere new.