While an exact cause of facial veins cannot be pinpointed with certainty, there are certain factors that may act as catalysts for the development of visible blood vessels in the face.  An interference in the circulatory function of the body is the main culprit; this interference may stem from a variety of stimuli which, in turn, causes blood vessels to become clogged, enlarged and visible. 

The circulatory system of the human body utilizes the heart, arteries and veins as the pump and respective vessels that carry the blood from the heart to the body, and back again. The arteries carry blood to the body and the veins carry blood back to the heart. If the veins or vein valves become weak, blood will drip back into the vessel and clog the pathway. The veins close to the surface of the skin will become visible through the skin. 

The three types of facial veins include: spider veins, reticular veins and varicose veins. The spider veins are the smallest; these are capillaries which have surfaced due to differing causes. The reticular veins are a medium size, can be a faint blue or green color, and are sometimes the cause of spider veins. Varicose veins are typically the largest and sometimes quite painful.

The following factors may influence a person's chances for suffering the circulatory problems associated with noticeable facial veins.

Heredity

Chances are good that if the faces of parents or grandparents show visible veins, the faces of their children have an increased risk of developing the same condition. Circulatory problems do indeed run in families, just as heart disease, atherosclerosis and stroke. The best preventive measure is living a healthy lifestyle. 

Getting Older

As people advance in years, all systems of the body age as well. Veins become less elastic, vein valves work less efficiently, and blood begins to pool in the vessel. The epidermis, or skin, of an older person gets thinner over time and veins may become more visible. 

Excess Sun Exposure

One of the detriments of too much ultraviolet light is damage to the outer layers of the skin. The damage may include the breakage of capillaries just below the surface of tender facial skin.

Physical Stress

Any activities placing undue stress on the face, such as excessive sneezing from allergies, repeated vomiting, and physical injury resulting in bruises, may exacerbate a predisposition to or cause facial veins.

Hormones, Pregnancy and Birth Control Pills

Since the body produces more estrogen during pregnancy, women may suffer vein weakness. Since blood flow is also increased, a woman's veins may become enlarged, causing blood to clog the vessels. Since birth control pills mimic pregnancy, the same consequences of pregnancy on vein health applies regarding the onset of facial veins. 

Rosacea

Rosacea is a disorder whereby a person's nose, cheeks, chin and forehead may become red, inflamed and swollen. The disorder, if left untreated for a prolonged period, may give way to facial veins. The most common form of facial veins stemming from rosacea are the spider veins or broken capillaries. Professional advice from a health care provider is necessary to treat the condition of rosacea itself and the ensuing facial veins.