This is a fact
Stress could be one of the reasons for excessive hair fall. Nervous habits, such as scratching of scalp, hair twisting or even hair pulling (also known as trichotillomania) may also be responsible for stress-related hair loss.
Hair fall due to stress is said to begin four to six months after the stressor happens. On a brighter note, this type of hair loss is usually not permanent. The amount of hair loss should return to normal once the source of stress is gone. However, if the condition persists, you may want to seek professional help.