The Warforged are constructs built using a variation off of magics that were employed during the Eldar War by the Dwarves to create war machines. Ritual magic is used to bind the soul of a soldier to his body, this allows limbs to be replaced with prosthetic replacements, or eventually the replacement of an entire body.
While their new body will invariably be more durable then their previous one being an artificial construct isn’t without its limitations. While the Warforged is aware of his body he does not “feel” it in the traditional sense and most of the creature comforts that help to make life enjoyable are denied to them.
Additionally most of the emotional attachment to the world is lost, this makes them more cold and distant then they were in life. This alteration can be especially painful for those that were close to the Warforged when they were Human, many of the wives of soldiers who return as warforged bitterly comment that they would have rather have had their husbands killed so they could mourn them then have them live on, while not being able to reciprocate the feelings of their spouses.
Living in a world without being able to enjoy food, a warm bed, sex, sleep and the hundreds of other little pleasures in life drives some Warforged insane, others throw themselves into their work, which means constant action on the front line where their not able to dwell on the pain they may have caused by choosing not to die.
Not all of the Warforged are miserable soulless automatons, the less tied to the comforts of life a person was before becoming a warforged the easier the transition is. Many revel in the separation from the distractions of mortality, while others who may have been somewhat passive in their mortal lives embrace what feeling and emotion they have left with new found zeal. It is not uncommon to see a Warforged energetically recounting their battle tales to the tune of a minstrel’s lute to an audience of his fellows who are only passively interested in his antics.