What is venous insufficiency?
Dysfunction of the veins, by which the veins in the legs are most often affected, is called venous weakness (in medical terminology, venous insufficiency).
Function of the veins
Once the arterial system has transported oxygenated blood and nutrients to the outermost parts of the body, the venous system transports the blood back to the heart. The veins in the legs in particular have to pump the blood upwards against gravity. This is done by the leg muscles that squeeze the veins together every time they contract (calf muscle pump). Like non-return valves, the venous valves prevent the blood from flowing back down into the legs and pooling there.
How venous insufficiency develops
If the venous valves no longer close tightly, the blood in the veins can flow back down and it becomes congested and pools in the lower parts of the legs. The vein walls capitulate against the higher pressure and the veins widen. The result of this is that the venous valves now close even less than they did before. Moreover, the distended veins eventually become visible as thin spider veins and the larger veins as convoluted, bluish varicose veins, many of which also protrude conspicuously under the skin. The blood that has pooled in the veins also leads to fluid leaking out into the surrounding tissues. Therefore, swollen legs and thick ankles are also a sign of venous insufficiency. If the disease continues to progress further, doctors call it chronic venous insufficiency (CVI).
Causes of venous insufficiency
The risk of developing venous insufficiency rises with increasing age, usually those over 50. Someone with a history of blood clots is also at a higher risk. Women are far more often affected than men. The reasons for this are the different structures of female connective tissue and the female hormone estrogen. This is why venous insufficiency also develops more frequently during pregnancy because the estrogen concentration is particularly high during this time. Hereditary predisposition is also a cause of venous insufficiency. In this case, several members of the family may suffer from the disease. Obesity and activities that require long periods of standing or sitting can also favor the onset of venous insufficiency.
What happens if venous insufficiency is not treated
Without treatment, the pressure and swelling can burst the tiny blood vessels in your legs called capillaries. This could turn your skin reddish-brown, especially at the ankles. This can lead to swelling and ulcers. These ulcers are tough to heal. Venous insufficiency is the trigger for a whole series of symptoms and disorders with increasingly grave consequences:
At the first sign of venous insufficiency, such as painful, tired, heavy or swollen legs, and spider veins and varicose veins, a specialist (phlebologist, angiologist, vascular surgeon or dermatologist) should examine your legs. With an ultrasound examination (Doppler ultrasonography), the doctor can judge the state of your venous system and can recognize disorders and blood clots that may have formed.
If the venous system proves to be weak and is not treated promptly, it may progress to varicose veins and thromboses that also affect the deep venous system as a condition call deep vein thrombosis. If blood clots become dislodged from the thrombosis, this could lead to a life-threatening pulmonary embolism. Venous leg ulcers (ulcus cruris) is another effect of chronic venous insufficiency.
Tips for everyday living to prevent venous insufficiency
- Avoid sitting or standing for long periods
- Go for regular walks
- Take the stairs, not the elevator
- Activate the legs’ muscle pump with sports such as swimming, cycling and power walking
- Strengthen your veins with vein exercises
- Alternating hot and cold showers strengthen the vascular system
- Make sure you drink enough water
- Keep your weight down
- Limit your use of high heels
- Wear medical compression stockings as soon as you notice the first signs of early venous insufficiency
Diminishing venous pressure
Venous pressure is a term that represents the average blood pressure within the venous compartment. Venous pressure diminishes continually from the ankle towards the heart. When standing still, venous pressure is generally 90 to 110 mmHg at the ankle. Accordingly, a person’s height is decisive for the resting venous pressure when standing. As we move around, the pressure reduces to about 20 mmHg as long as sufficiently good venous drainage is guaranteed. Several factors are important for venous return to the heart.
The action of the heart towards the periphery (retrograde force)
In adults with healthy hearts, an average of about 2.5 ounces of blood is pressed from the left ventricle into the aorta during each ejection phase. This volume of blood exerts additional (to the already existing) pressure on the column of blood in the aorta and the arteries surrounding it. This “pushes” the blood further through the vascular system via the arterial side of the capillary system into the venules and from there via the veins in the direction of the right side of the heart.
The larger the venous diameter in the direction of the heart, the lower the prevailing pressure. In a healthy person lying down, the pressure in the venous capillaries is about 20 mmHg; it falls to about 8 – 12 mmHg in the groin, measures around 3 – 5 (mmHg) in the abdominal cavity (intra-abdominal), and only 2 mmHg in the right atrium.
These pressures are adequate for the return transport of the blood. The suction action of the heart only comes into play in the final venous segment, i.e. shortly before the upper vena cava opens into the right atrium. This suction occurs during the ejection phase and is generated by the movements of the valves in the heart
Suction caused by breathing
The pressure in the chest is negative. As we inhale, this negative pressure increases, and, at the same time, the intra-abdominal pressure rises as the diaphragm moves downwards. This causes the venous valves in the femoral vein to close.
When we exhale, the valves open again as a reaction to the fall in intra-abdominal pressure. As a result, the pelvic veins and the inferior vena cava fill with blood again, which then flows further in the direction of the heart. This so-called abdominal-thoracic two-phase pump is boosted by the heart’s activity.
The blood in the veins exerts pressure on the vein’s wall. This generates tension in the venous wall, which serves as counterpressure for the blood and ensures that the venous pressure does not increase further. Venous pressure and venous blood volume are closely related.
The muscle pump
The deep venous system is embedded in muscles. Due to this, every muscle contraction squeezes the veins to push the column of blood in them in the direction of the heart. When the muscle relaxes, the venous valves prevent the retrograde flow of blood towards the capillaries.
Only a certain amount of blood is transported in the direction of the heart with each muscle contraction. In this connection, the most important role is played by the calf muscles. However, efficient venous valves are essential for effective “drainage”.
Overall, it must be remembered that the transport of blood in the veins is passive and depends on the interaction between several factors. If only one of these factors is impaired, in confinement to bed, for example, the calf muscle pump is dormant, and venous return flow disorders may develop. This can, in turn, cause thromboses or even thrombo-embolisms.
Venous inflammation (phlebitis)
Usually, the superficial veins are affected (superficial phlebitis). The inflammation occurs often in connection with varicose veins in the veins of the legs, although the veins of the arms and, rarely, the veins of the face and neck can also be affected. As a rule, phlebitis is restricted locally and can sometimes be very painful. The affected segment of the vein is visible as a red, warm, and often swollen area on the skin. Inflammation caused by bacteria may cause fever.
A specialist (phlebologist, angiologist, vascular surgeon, dermatologist) must be consulted immediately: blood clots (thromboses) may develop as a result of venous inflammation. If a deep leg vein is inflamed, this may cause a thrombosis that is also called deep vein thrombosis or phlebothrombosis.
If the thrombosis is swept into the lung, this is called a pulmonary embolism, and it can be lethal.
Causes of venous inflammation
A slower blood flow is the most common cause of venous inflammation. It leads to inflammatory reactions on the weakened venous wall that is often predisposed by varicose veins. But venous inflammation can also occur where the vein is squeezed together over long periods by overly tight clothing or, for example, the edge of a hard chair. Another common cause is catheters that doctors place for infusions or giving medication and remain in the vein for several days. Venous inflammation can also be caused by an injury to the venous wall or by penetrating bacteria. It can also arise after operations and longer periods of confinement to a bed.
What happens if venous inflammation remains untreated?
A slower blood flow is the most common cause of venous inflammation. It leads to inflammatory reactions on Inflammation of superficial veins that are diagnosed and treated promptly and often regresses within a few days without any complications. If the symptoms of venous inflammation remain untreated, it may spread and can cause pain lasting several weeks. The situation is especially precarious if the venous inflammation remains untreated as it may spread and cause pain lasting several weeks. The situation can worsen if the venous inflammation occurs near a branch in the deep venous system. If this is left untreated, it may cause deep vein thrombosis with the risk of a dangerous pulmonary embolism.