What is a Birthmark?
Birthmarks are marks that appear on the skin during or after birth, usually brown, red or purple. These marks are sometimes congenital and become more visible on the skin over time, while sometimes they can develop after birth. These marks, which are generally harmless, can be treated for aesthetic concerns.

Genetic Factors
The most common cause of birthmarks is genetic factors. If someone in your family has a birthmark, you are more likely to develop such marks. Familial predisposition can affect how the pigmentation of the skin develops, which can cause birthmarks to form.

Skin Vascular Dilation
Some birthmarks occur as a result of the dilation of the veins under the skin. This usually leads to reddish or purple-toned spots. When the veins are directly close to the skin surface, such spots become more visible. This situation can be genetic, as well as environmental factors or different change processes in the body.

Hormonal Changes
Hormonal changes are another important factor in the formation of birthmarks. Changes in hormone levels, especially during pregnancy, can lead to increased pigment production in the skin. In this case, brown or dark spots can form on the skin. In addition, as hormone levels return to normal after birth, these spots may decrease in size.

Sunlight and UV Effects
Long-term exposure to the sun can increase pigment production in the skin and cause birthmarks to become more visible. Sunlight can stimulate the skin's melanin production, causing the spots to darken. Therefore, applying sunscreen to areas where birthmarks are present is important to prevent the appearance of the spot.

Skin Trauma and Injuries
Another cause of birthmarks on the skin is trauma. If there is an injury, cut or any physical impact on the skin, this can increase pigment production and cause birthmarks to form. In addition, intervention on spots that have already formed on the skin can also lead to the formation of such spots.

In Conclusion
The causes of birthmarks are usually related to genetic, environmental and hormonal factors. Most birthmarks are harmless and can disappear on their own over time, but they can be treated for aesthetic reasons. If you are concerned about birthmarks, you can talk to a dermatologist to learn about the most appropriate treatment options.