First up, alopecia simply is a medical term for hair loss. When your hairdresser proclaims with a grave tone that you have “alopecia”, he/she is simply suggesting that you have hair loss (and that he/she just so happen to have this magical shampoo which would restore your scalp furriness. You, being a loyal customer, could have this magical potion for eighty bucks as a major discount.)
“Alopecia areata” refers to a specific medical condition in which there are circular patches of hair loss scattering over the scalp (and/or other hairy areas). More later…