This type of hair loss occurs in response to certain stressful events. Sudden and severe stress causes an increase in the amount of the hairs being shed. The source of stress resulting in hair loss can be events such as childbirth, pregnancy termination, starting or stopping the use of oral contraceptive drugs, premenopausal period, drugs used in diet regimens, some emotional stresses etc. These events will cause the hair to stay in the resting phase for about only 3 months. Then, a large amount of hair will be shed.