Transcript for Is the 'Man Bun' Contributing to Baldness?
You could skirt the issue. It mat enarerff t?two wos: Irdt heals. Wi death HT. Un clikereams and rubs THA matsk then, Pai Th ermaca and lieu Pete that nyong'o rocking top knot. Men stepping up the hair game with the man bun. You can see it in Hollywood. It's kind of cool and kind of hot. Reporter: Could this look be hurting your lox. You shouldn't be wearing your hair pulled back that tight. That long-standing pull on traction on the hair could pull the hair out and ultimately lead to permanent scarring, which is something we call traction alopecia. Reporter: Caused by scarring the hair follicles by wearing your hair too tight and too often. Here's proof. Reporter: Sometimes, with disastrous effects. Once the follicle is scarred, the hair is permanently lost. It won't grow back. Reporter: This expert says you don't have to sur trend bun completely. You can get the same look slicked back. Reporter: Keep these don'ts in mind when tieing the perfect topknot or man bun. Not damp or wet hair. Don't pull the hair while it's -- secured with elastic. Now, to avoid the hair loss associated with topknots, doctors say not to pull the hair so tight. That puts on the stress. Kayna is here with the right way to do that. As you can see, they, not Jesse, not me. They have pulled my hair back. They left new give so the follicles around my forehead can breathe. They couldn't get his hair in a topknot. A good rule of them is to allow enough space, to go back to the '80s, put a pencil in there. They did it perfect. Yeah? See. See that. You're supposed to be able to put a pencil there. You're not too tight. Boom. You're welcome, America. A good rule of thumb for men, no topknot. Well done. Well done. Amen, George. Back to you, America. Jesse, kayna, thank you.
This transcript has been automatically generated and may not be 100% accurate.