Is hair loss a result of aging?

No: Depends on the type of hair loss. Male pattern hair loss is more common as one grws loder. It is an occurrence more common with age but is not caused by age.

Sometimes: Aging related hair loss is called androgenetic alopecia. This is due to gradual minaturization of the follicles over time. Over-the-counter rogaine (generic=minoxidil) stops this process for as long as you use it. However, if you stop, the minaturization process begins again and hair loss restarts as though you've never used it before. So, for rogaine to work, you must use it for life.