A pathological liar is usually defined as someone who lies incessantly to get their way and does so with little concern for others. Pathological lying is often viewed as coping mechanism developed in early childhood and it is often associated with some other type of mental health disorder. A pathological liar is often goal-oriented (i.e., lying is focused - it is done to get one's way). Pathological liars have little regard or respect for the rights and feelings of others. A pathological liar often comes across as being manipulative, cunning and self-centered.

A compulsive liar is defined as someone who lies out of habit. Lying is their normal and reflexive way of responding to questions. Compulsive liars bend the truth about everything, large and small. For a compulsive liar, telling the truth is very awkward and uncomfortable while lying feels right. Compulsive lying is usually thought to develop in early childhood, due to being placed in an environment where lying was necessary. For the most part, compulsive liars are not overly manipulative and cunning (see, Pathological Liar), rather they simply lie out of habit - an automatic response which is hard to break and one that takes its toll on a relationship

The terms Habitual Liar and Chronic Liar are often used to refer to a Compulsive Liar.

Ultimately, making this type of distinction may not be all that useful. Because in either case, the outcome is typically the same: dealing with a compulsive or pathological liar is very difficult to do.

A compulsive liar will resort to telling lies, regardless of the situation. Again, everyone lies from time to time , but for a compulsive liar, telling lies is routine; it becomes a habit and a way of life.

Simply put, for a compulsive liar, lying becomes second nature.

Not only do compulsive liars bend the truth about issues large and small, but they take comfort in it. Lying feels right to a compulsive liar. Telling the truth, on the other hand, is difficult and uncomfortable for a compulsive liar to do.

And like any other behavior which provides comfort and an escape from discomfort (i.e., alcohol, drugs, sex), lying can become addictive and hard to stop. For the compulsive liar, lying feels safe and this fuels the desire to lie even more.

Making matters even more complicated, compulsive lying is often a symptom of a much larger personality disorder, which only makes the problem more difficult to resolve .

Unfortunately, compulsive lying is hard for the person involved to see, but it hurts those who are around it. Compulsive lying, if not addressed, can easily destroy a relationship.

Compulsive lying can be dealt with through counseling or therapy. But, like many addictive behaviors (and/or personality disorders), getting someone to admit they have a problem with lying is the difficult part. Sadly enough, getting someone to recognize that he or she has a problem usually requires hitting rock bottom first.