What is a klesha? - found it as a word in a Buddhist book.

[Wesley1982]

What is a klesha? I'm guessing it has something to do with impure perception.

[Kunga Lhadzom]

I just Googled it : http://en.wikipedia.org/wiki/Kleshas_%28Buddhism%29

[jeeprs]

Klesha (Pali Kilesa) is 'defilement' or 'obstruction' - that which prevents one from 'seeing things as they truly are' by distorting your understanding of the nature of reality and manifest as unskillful actions. It is an important term in Buddhist ethics. It is somewhat equivalent to a now disused Christian term, beginning with s, three letters, that it is no longer considered 'skillful' to use.

[Wesley1982]

I see from the Wiki source - do many with substance abuse issues have this "Klesha" going on in their situation?..

[Kunga Lhadzom]

substance abuse

I'd say yes, because it's attachment, and something that is abusive is obviously a poison for your mind and body, right ? If it's not hurting you,(like medicinal use of weed for cancer patients, to aleviate the suffering of nausea),
then it's not really abusive (IMO). But abusing the law has consequenses.

[Wesley1982]

substance abuse

I'd say yes, because it's attachment, and something that is abusive is obviously a poison for your mind and body, right ?

Yes.

A narcotic introduced to the brain chemistry causes an adaptive change leading to chemical dependency.