What most naturally follows?

How to treat thinning hair 
See if hormonal causes are at play. 
The most common cause of thinning hair for both men and women is a hereditary condition in which sex hormones cause hair to fall out in a particular pattern. While male or female pattern baldness is permanent, there are certainly measures you can take to slow it down and treat it.
Sometimes hormonal fluctuations lead to impermanent hair loss. Women who are pregnant, have discontinued birth control, or are going through menopause may experience temporary hair thinning.