Resently iv noticed lots obvious and dark veins under my skin, on the inside of my arms, my legs etc, iv also had dark circles and veins around my eyes what could be causing this? i'm 18 and female

Doctor can evaluate: Increased visibility of veins, dark veins, dark circles under the eyes, etc..., are usually due to increased blood in the tiny veins and capillaries in the skin. If the skin thins out, one may see a similar appearance. A primary care doctor can evaluate to be sure the patient is healthy, and look for causes of the increased appearance of veins, such as hormonal causes, medicine effects, etc...

Not concerning.: The prominence of veins through the skin is affected by many factors including levels of hydration, hormones, body temperature as well as outside temperature, medications and even levels of stress. Fair skinned people tend to have more easily visible veins than darker individuals and hereditary plays a strong role also. In a healthy person, visible veins are usually not of any concern.