You and your client have gone through a lot together. You heard about all of her college boyfriends, her first job. She celebrated your marriage and the birth of your first child. And you've had fun—from the various cuts you've done to taking several turns on the color wheel to change up her look. But now you're facing a new challenge—hair loss. Hair loss and thinning hair are common issues many of your clients will face—78 percent of people, male and female, will experience thinning hair at some point in their lifetime. It's a tough conversation to have—but…