When a person becomes overly needy or pushy, they can push others away. People might not feel comfortable being around a needy or pushy person.
Busy people and those who have tight schedules usually avoid those who can waste their time. If you talk non-stop or if you don't know when to stop talking, a busy person might avoid you. See also the Type A personality.
Some people avoid the ones who like them aromatically. If your behavior is so obvious and if the person you are interested in is not interested in you, they might avoid you. See signs someone likes you.
If a person is not feeling good, they might want to avoid people, especially the ones they don't know very well. People can sometimes be in need of their private space.
If you annoy people in any possible way without realizing that you are doing it, people might respond by avoiding you.
If some people dislike you, because of any reason, they might try to avoid you. Understanding how people think and what makes them like others can be useful in this case. See why could people hate you for no reason.
If you don't have proper social skills, some people might not be comfortable dealing with you. In such a case, those people might try to avoid you.
If you seem unfriendly, intimidating, not social or even hostile, people might avoid you. In such a case, people would be doing so because they feel uncomfortable around you.
Jealousy can prevent people from becoming friends with others and can also ruin current relationships. If a person starts getting jealous of you, they might avoid you. See how to identify jealous people.
If you hurt people with your words, if you criticize them often or if you ask too many personal questions, you might make people feel uncomfortable around you. Once this happens, people can start avoiding you.
If the popular people in a group avoid you, others might try to do the same just to fit in. This is very common in schools where a whole group can try to avoid a person.
According to psychologists, perception errors can result in ruining social relationships. People might be acting normal yet you might be thinking that they are avoiding you.
People can get very annoyed of egoistic ones who keep talking about themselves. If you always talk about yourself and how great you are, know that you might be pushing people away.