I know the cause of windpuffs, and that most are not a serious problem and they are common in older hard working horses. My question is what would you think about them in a younger horse? Under the age of 6.
I tend to agree with dwblover. My STB came to me off the track right after he turned 6 with wind puffs. He had nearly 100 starts in his career, so it wasn't completely shocking. I've had him 8 and a half years now and they haven't caused any problems or gotten any bigger. I've had similar experiences with OTTBs, too.
If you are looking at a horse to purchase, then definitely do a PPE and ask the vet about them. In general, though, wind puffs don't really bother me.
They point to an area that is stressed, or has been stressed so much they are now permanent. My mare has them on both hind fetlocks, because she toes out. Not really a big deal, unless you ignore them, and that stress causes a bigger issue.
Keep an eye out to see if it's a conformation issue, a trimming problem, and footing/riding/training problem, or a combination of everything. Once you figure out what that stress is, you can prevent it from happening.
"On the back of a horse I felt whole, complete, connected to that vital place in the center of me...and the chaos within me found balance."
It is not my horse, just a horse I know. I do have experience with them in older horses that have worked hard for quite a few years. The owner is not worried about them, but I wasn't sure about concern for them in a younger horse that has not worked super hard (ie is not off the track or anything) just a riding horse.
I was at a boarding barn a few years back and the arena had very deep footing that was not well maintained, several horses suddenly got windpuffs and we all figured it was the stress of extra deep, irregular footing.