5-Damage from chemicals.
Use of chemicals on hair lead to hair thinning, which eventually contributes to hair loss. Most people want to enhance how their hair looks through chemical means but worry about hair loss. Now, if you really want to use chemicals on your hair, its best to consult with or get it done by a licensed beautician. Avoid performing chemical treatments by yourself, you might over apply these chemicals on your scalp, which is very dangerous to your hair follicles.