Spider veins normally appear on the face, neck, upper arms or thighs and are often characterized by a small round, red spot with tiny red veins radiating outward like the legs of a spider. This condition is known as spider angioma or spider telangiectasia. It is usually harmless to your health but is treated for cosmetic reasons. Varicose veins and spider telangiectasia are the visible surface manifestations of a possible venous insufficiency syndrome. Venous insufficiency syndromes allow venous blood to escape from a normal flow path and flow in a retrograde direction into an already congested leg. Mild forms of venous insufficiency are merely uncomfortable, annoying, or cosmetically disfiguring, but severe venous disease can produce serious systemic consequences and can lead to loss of life or limb. Varicose and spider veins are normal veins that have dilated under the influence of increased venous pressure.

In the case of healthy veins, one-way valves direct the flow of venous blood upwards and inwards, blood is collected in superficial venous capillaries, flows into larger superficial veins, and eventually passes through valves into the deep veins, then centrally to the heart and lungs. Capillaries are the numerous tiny tubes that arise directly from the arterioles and met-arterioles, they form networks or beds in the skin, organs and tissues. Capillary blood pressure differs from organ to organ. In the glomeruli (kidneys), it is about 57 mmHg, in the lungs only 6mmHg and about 28 mmHg in the skin and muscles.

Capillaries have very thin walls (1 μm thick), consisting of a single layer of squamous endothelial cells surrounded by an extremely thin basement membrane. They do not contain muscle fibers and have no nerve supply. Structurally speaking you find three types of capillaries; Continuous (nonfenestrated) capillaries found in the brain, fenestrated capillaries found in the intestinal organs, and discontinuous capillaries (sinusoids) found between endothelial cells that allow the exchange of large molecules. The capillary flow is mainly controlled by the muscle fibers firming the junction between the arteriole and the capillary. 

The prime function of the cardiovascular system, specifically to supply nutrients and oxygen to the tissues and to remove waste products, is realized at the capillaries through diffusion, filtration, active transport and pinocytosis. The factors determining the balance between filtration re-absorption were originally formulated by Starling and refer to as Starling’s Hypothesis of Transcapillary Balance.

Fresh ruptures present as bright red “Spider Veins”. Finding the point where the capillary has ruptured, will lead you to the feeding point of the “Spider Vein”. Dark blue or purple “Spider Veins” are representative of a network of broken capillaries and blood molecules captured between the tissue cells, where the lymph system is unable to disperse of the dead blood molecules.

CAUSES OF SPIDER VEINS

There are various reasons to why the thin membrane of the capillary ruptures and allows blood molecules to move in between the tissue cells, forming spider web like paths of blood. Chemical and hormonal changes in the tissue and cells play a big part. Inactive or slow lymph drainage system, blood pressure, the body’s pH balance and physical damage are the major reasons for broken capillaries.

The main cause for both varicose and spider veins, is hereditary. The risk of developing these leg vein problems increases for pregnant women or women who are using birth control pills, because hormones such as oestrogen can further weaken vein walls. Obesity and lack of exercise, which weaken the system of leg veins, are also factors. The "second heart" is a system of muscles, veins and valves in the calf and foot that work together as a pump to keep blood moving toward the heart against gravity. This system, though strong and capable of carrying tremendous weight and pressure, has a weak link: the venous (vein) system. Like the heart in our chest, the second heart stays healthy through regular exercise.

The risk of developing varicose veins increases with age for both men and women. The natural pH balance of the body and the acidity in the cells also play a big part. If the acidity levels in the blood is too high it causes the blood to thicken and the additional pressure on already weak capillaries or veins, causes the vein to rupture, allowing the blood to flow through and seep in between the tissue cells. Perfectly normal veins dilate and become tortuous (winding) in response to continued high pressure, as is observed in patients with dialysis shunts or with spontaneous arteriovenous malformations. In a subset of patients with hereditary vein wall weakness, even normal venous pressures produce varicose changes and venous insufficiency.

In the most common scenario, a single venous valve fails and creates a high-pressure leak between the deep and superficial systems. High pressure within the superficial system causes local dilatation, which leads to sequential failure of other nearby valves in the superficial veins. After a series of valves have failed, the involved veins are no longer capable of directing blood upward and inward. Without functioning valves, venous blood flows in the direction of the pressure gradient: outward and downward into an already congested leg.