Trichoptilosis (from the Greek τριχο- tricho- "hair" and the New Latin ptilosis "arrangement of feathers in definite areas" from the Greek πτίλον ptilon "feather"), schizotrichia, and informally split ends, is the splitting or fraying of the hair-shaft due to excessive heat and mechanical stress.
[2] The most common type of split ends, where the single hair forks into two.
[4] Thermal, chemical or mechanical stress can cause split ends.
For example, the use of curling irons and other heat treatments may cause split ends.
Split ends can be a symptom of copper transport disorders such as Menkes disease and occipital horn syndrome.