Why Do People Have Birthmarks?

Why do people have birthmarks? Doctors don't really know. There are a few types of birthmarks that can be symptoms of a bigger problem. Occasionally, birthmarks seem to have a genetic link. However, most birthmarks simply form before or a few weeks after birth with no apparent explanation. The marks simply seem to be a random side effect of developing and growing a human body.
Birthmark Types
Birthmarks can be raised or flat, big or small, and almost any color. The most common colors for birthmarks are black, blue, brown, purple or red. The two basic birthmark types are vascular and pigmented. Vascular birthmarks occur when blood vessels over develop, cluster or grow in knots. Pigmented birthmarks occur when pigment cells form in clusters.
Vascular Birthmarks
Port wine, hemangiomas and salmon patch are the three most common types of vascular birthmarks. Port wine marks are deep red or purple patches that can grow in size or darken as the child grows. Most of these marks are harmless and can be treated if necessary. Nevertheless, the mark should be checked by a doctor to determine if it's a symptom of Klippel-Trenaunay or Beckwith-Wiedemann syndrome.
Hemangiomas vascular birthmarks can grow at or below the skin's surface. They appear red when at the surface of the skin and bluish when below the surface. The usually grow for the first few years of life and then begin to recede. The deeper marks may leave a scar as they recede. Treatment is available if the growth or scar become problematic. Salmon patches are small and light marks that may or may not vanish as the child ages. They require no treatment.
Pigmented Birthmarks
Cafe-au-lait spots, moles and Mongolian spots are the three most common types of pigmented birthmarks. Café-au-lait spots are flat and light brown patches that can occur anywhere on the body. Though they don't usually require treatment, the spots should be checked at birth to determine if they are a result of the genetic disease neurofibromatosis.
Moles are the most common type of pigmented birthmarks. They can be flat or raised, any size and any color. Most moles are harmless and do not go away with age, but treatment is available if they become problematic. Mongolian spots are bluish, bruise-like spots usually located around the lower back, buttocks and upper legs. They require no treatment and usually vanish with age.
Birthmark Care
Birthmarks should always be checked by a doctor at birth to determine if they are harmless or a symptom of a problem. Most birthmarks, such as moles, should be checked occasionally by a doctor as you age to determine if the mark is still harmless. You should also visit a doctor if any birthmark experiences unexplained bleeding, oozing, itching, rapid-growth or dramatic color change.
Most birthmarks, especially ones darker than your skin, are susceptible to sunburns. You need to take life-long preventative care by keeping the marks covered with sun block when possible. The darker color absorbs even more of the sunlight than your normal skin color, making the marks more susceptible to becoming cancerous.