DIAGNOSIS -  To determine hair condition, we look into the hair's elasticity and porosity.. To determine elasticity, dampen a section of hair at the crown. Hold a strand out from the head and carefully stretch it between the thumb and index fingers. Release the tension: if the hair returns to its normal length, it has good elasticity! If it remains stretched, or even breaks, the elasticity is poor. Porosity is the hair's ability to absorb and hold moisture: porous hair is dull-looking, has more open cuticle and feels rough. Tenacity represents the ease or difficulty with which the cuticle can be penetrated.. Tenacious hair is shiny with out appearing glossy. The cuticle is intact and feels smooth.