Individuals should first seek the help of a qualified doctor to identify what is causing the hair loss to occur. The most common factor would be genetics. This is not always evident from family history. Also, there may also be other reasons such as:(1) side effects from prescription drugs(2) thyroid imbalances(3) telogen effluvium (physiological stress)A doctor can perform tests and issue an official diagnosis. From this information, an appropriate course of action can be determined. For example, stopping prescription medications or changing their dosage may cause hair to regrow back to normal. Telogen effluvium is when the follicles enter the resting telogen phase much sooner than they normally would. This is often caused by some type of stress (e.g. drastic diet change). Identifying this may help address the core issue.