Spider veins are red or purple delicate clusters of veins marking your skin surface.  They are also known as known as broken capillaries or telangiectasia. They form mostly on the legs, but also arise on the face and other areas. Sometimes they resemble a spider. Other times they look more like a tiny branching bush or a stack of thin, separate lines.

Spider veins are small clumps of unessential blood vessels that are located near the surface of the skin and have expanded, becoming visible. A number of factors may help trigger their appearance, including genetic makeup, pregnancy, excess sun exposure, weight gain, certain medications, and birth control pills, as well as trauma to the skin, like a hard pinch.

Sometimes the veins trigger aching, swelling, burning, and cramping, but usually they are no health hazard. 

Varicose veins are enlarged, twisted veins with nonfunctioning valves, usually in the subcutaneous tissues of the leg. They result from a stagnated or sluggish flow of the blood,  in combination with defective valves and weakened walls of the veins.

Varicose veins occur most frequently in those who must stand or sit motionless for long periods of time. Pregnancy is sometimes responsible for the development of the condition. It also appears that a tendency to develop varicose veins may be inherited.

Symptoms: The development of varicose veins is usually gradual. There may be feelings of fatigue in the legs and leg cramps at night; a continual dull ache may develop in the legs,  and the ankles may swell.  If the condition is untreated and allowed to spread,  as it often does,  the veins become thick and hard to the touch,  and dull or stabbing pains may be felt in time. 

Causes:  Blood returning to the heart from the legs must flow upward through the veins,  against the pull of gravity. This blood is "milked" upward principally by the massaging action of the muscles against the veins. To prevent the blood from flowing backward,  the veins contain flaplike valves,  located at frequent intervals and operating in pairs. When the blood is flowing toward the heart,  the venous valves are open and the blood can move freely. If the blood should attempt to flow backward,  the valves close,  effectively stopping the reverse movement of the blood.

Prolonged periods of standing or sitting without movement place a heavy strain on the veins. Without the massaging action of the muscles,  the blood tends to back up. The weight of blood continually pressing downward against the closed venous valves causes the veins to distend; after a time,  they lose their natural elasticity. When a number of valves no longer function efficiently,  the blood collects in the veins,  which gradually become swollen and more distended.

During pregnancy,  more force often is necessary to push the blood through the veins because the pregnant uterus tends to press against the veins coming from the legs and thus prevents the free flow of blood. This increased back pressure can result in varicose veins.