Rosacea is a condition where redness appears due to the presence of:
small, dilated red blood vessels visible on the face. Rosacea occurs due to poor elasticity of the capillary walls. Normally, when there is a sudden rush of blood to the skin, capillaries expand to receive the increase of blood, then contract and return to normal. In a weakened state of elasticity, however, capillaries will expand, but do not contract and return to their normal state. This results in dilated capillaries with lingering blood cells, making them appear defined and red on the skin’s surface.
Rosacea is often caused by certain hereditary factors: skin that is structurally thin and sensitive, and weak capillary walls. Exposure to extreme cold, harsh winds or extreme heat can also contribute to this condition. All skin types can be prone to redness, the only factor they have in common is structural thinness. Often structural changes in aging skin can contribute to rosacea.
Especially people of North-Western European origin with a relatively light skin type can experience an increase in the blood vessels.