About 1 to 2 percent of the human population has red hair.
Redheads have genes to thank for their tresses. Research shows red hair usually results from a mutation in a gene called MC1R, which codes for the melanocortin-1 receptor. The pigment found in redhair that makes it red is called pheomelanin.
But redheads as a group have more in common than only their hair color -- certain health conditions appear to be more common among people with red hair.
Here are five health risks linked with being a redhead.