What mostly causes estrogen levels to rise in a man?

Can you answer K R’s question about Menopause?:

I seem to have developing breasts and more feminine features…..Mind you, I am not complaining about it, but it seems my inner estrogen level is going up as my testosterone level is going down….what would cause it?

Early Onset Menopause Symptoms

Tell me your experience with male HRT please?

Can you answer fetishking7’s question about Menopause?:

When did you start hormone replacement therapy? Any negative side effects? Would you recommend it or should guys look for alternative ways of reaching normal testosterone levels? Tell me anything and everything you want about HRT. Thanks.

Alternatives To Hysterectomy