I found this article over at BlackGirlLongHair.com about 7 signs your hair MIGHT be damaged.
I found this interesting because often times we may think we have a pretty healthy head of hair and don't realize we are probably doing a healthy about of damage to it.
I always try to counter-act the damage I could possibly be doing to my hair by keeping it moisturized and doing search and destroys to try to cut out on any severe breakage... but check out this article and see if any of this fits your hair!
NOTE: I say "might" for some of these because everyone hair is different... especially for African American hair. Tangled hair... or hair dye absorbency isn't necessarily an indicator of unhealthy hair.
Check out the article here