Every day, most people lose approximately 100 hairs from their heads. But nobody notices, because nearly 100,000 strands remain. It is only when the 100 lost ones aren’t replaced by 100 new ones growing in that someone goes bald.
Usually hair loss isn’t obvious until someone loses more than 50 percent of the hair on their head. But the loss can start surreptitiously, sometimes with men in their 20s and women in their 30s or 40s.