* Damage to the Hair Structure: Bleach works by opening the hair cuticle and oxidizing the melanin (pigment). When done improperly, it can severely weaken the hair's protein structure (keratin). This makes the hair brittle, dry, and prone to breakage.
* Overlapping: Applying bleach to previously bleached areas causes further damage. The already weakened hair can snap off.
* Using Too Strong of a Developer: The developer (hydrogen peroxide) strength is crucial. A developer that is too strong can speed up the bleaching process, causing excessive damage.
* Leaving the Bleach on Too Long: The longer the bleach stays on, the more damage it does. It is possible to actually melt the hair.
* Scalp Burns: If the bleach is applied too close to the scalp or the formula is too strong, it can burn the scalp, leading to hair loss in the affected areas.
Important Considerations:
* Hair Loss vs. Breakage: It's important to distinguish between hair falling out at the root (hair loss) and hair breaking off along the shaft (breakage). Bad bleaching typically causes breakage due to damage to the hair strand, not hair loss at the root. However, scalp burns from bleach can cause hair loss at the root.
* Professional Help: The best way to prevent damage is to have your hair bleached by a professional. They can assess your hair's condition, choose the appropriate developer and bleach, and monitor the process.
* Rebuilding Hair: If your hair has been severely damaged, you can take steps to try to rebuild the hair. Protein masks are a great way to do this. Also be sure to use moisturizing products such as hair masks and leave-in conditioners.