These words are all used to show contrast. The difference is where we place them in the sentence. Although and even though are used at the beginning of a sentence or clause - never at the end:

Although I exercise a lot, I can never seem to lose any weight.

Even though I exercise a lot, I can never seem to lose any weight.

I exercise a lot. I can never seem to lose any weight, although though.

I can never seem to lose any weight, although/though/even though I exercise a lot. (all three are correct)

All three can be used in the middle of a sentence, as in the final example.

Fact
Spiral staircases in medieval castles are running clockwise. This is because all knights used to be right-handed. When the intruding army would climb the stairs they would not be able to use their right hand which was holding the sword because of the difficulties of climbing the stairs. Left-handed knights would have had no troubles, except left-handed people could never become knights because it was assumed that they were descendants of the devil      .. More >>