Can bread, mustache, Or any hair other than head hair fall down or break down?

Yes. Can be alopecia areata, fungus, various toxins, etc. See a dermatologist if you experience this.
Possible . Hair follicles which function to form hair are dependent on good nerve and blood supply and a healthy skin. Skin diseases, impaired blood and nerve supply, poor nutrition and hormonal imbalance are unhealthy for hair causing loss. .