Improper Hair Cosmetic Use / Improper Hair Care may lead to hair loss. Many men and women use chemical treatments on their hair, including dyes, tints, bleaches, straighteners and permanent waves.  These treatments rarely damage hair if they are done correctly.  However, the hair can become weak and break if any of these chemicals are used often.  If hair becomes brittle after chemical treatments, it’s best to stop these until the hairs have grown.
Hairstyles that pull on the hair like ponytails and tightly pulled braids should be alternated with looser hairstyles.  The constant pull causes some hair loss, especially along the sides of the scalp. This is known as traction alopecia. Hair loss may be reversible in early stages but it can lead to permanent hair loss in long standing situations.

Over-shampooing, -combing, and -brushing can also damage hair, causing it to break.  Using a cream rinse or a conditioner after shampooing will make hair easier to comb and more manageable.  When hair is wet, it is more fragile, so vigorous rubbing with a towel as well as rough combing and brushing should be avoided.  

Do select wide toothed combs and brushes with smooth tips. However, avoid following the old rule of 100 brush strokes a day —that may damage your hair too.