Deep Vein Thrombosis, Peripheral Vascular Disease
and Peripheral Artery Disease
Your body needs the right amount of blood flow to keep your heart pumping, your legs moving and your brain functioning. Blood circulation, the movement of blood throughout the body, is clearly crucial to your existence, and poor leg circulation can cause many problems for individuals around the world.
A common cause of poor leg circulation – restricted blood flow to your legs – is peripheral vascular disease, or PVD. This term refers to disorders involving blood vessels outside, or on the periphery, of the heart. PVD can involve peripheral arteries (blood vessels that carry blood away from the heart) or peripheral veins (blood vessels that carry blood toward the heart).
When PVD involves the arteries, it is known as peripheral artery disease, or PAD. A fatty substance called plaque builds up and hardens on the walls of the peripheral arteries, making it difficult for blood to properly flow through. The plaque takes years to build up, which is why older adults are more at risk.
In addition, the following behaviors or conditions can also contribute to foot, ankle and lower leg circulation problems:
If you have poor leg circulation, symptoms usually develop gradually.
Frequent suffering with cold feet and/or cold hands usually signifies that your circulation, or blood flow from your heart, has slowed. This may especially happen at night when you are trying to sleep, during periods of immobility or after eating certain foods.
People who have very poor leg circulation may also develop a blood clot, a sudden blockage in blood that can cause severe leg pain. This blood clot, known as deep vein thrombosis (DVT), develops in a deep vein, and can occur when a vein is damaged or if blood flow slows down or stops completely. If you’re obese and/or over age 40, you’re at particular risk for DVT.
When a blood clot forms in a leg vein it usually remains stuck to the vein wall. The symptoms tend to settle gradually. But, there are two main possible complications:
In a small number of people who have a DVT, a part of the blood clot 'breaks off'. This travels in the bloodstream and is called an embolus. An embolus will travel in the bloodstream until it becomes stuck. An embolus that comes from a clot in a leg vein will be carried up the larger leg veins to the heart, through the large heart chambers, but will get stuck in a blood vessel going to a lung. This is called a pulmonary embolus. A small pulmonary embolus may not cause any symptoms. A medium sized pulmonary embolus can cause breathing problems and chest pain. A large pulmonary embolus can cause collapse and sudden death.
Without treatment, up to 6 in 10 people who have a DVT develop long-term symptoms in the calf. This is called 'post-thrombotic syndrome'. Symptoms occur because the increased flow and pressure of the diverted blood in other veins can affect the tissues of the calf. Symptoms can range from mild to severe and include: calf pain, discomfort, swelling, and rashes. An ulcer on the skin of the calf may develop in severe cases. Post-thrombotic syndrome is more likely to occur if the DVT occurs in a thigh vein, or extends up into a thigh vein from a calf vein.
Phlegmasia Alba Dolens (Blue Leg)
Progression of the clotting process in the vein may lead to increased swelling. This can cause a global compromise of the circulation in the limb, affecting both the arteries and the veins. This complication is called phlegmasia alba dolens and may lead to gangrene, requiring amputation of the affected limb.
Treatment and Prevention
The aims of treatment are:
Anticoagulation - preventing the
clot from getting bigger
Anticoagulation is often called 'thinning the blood'. However, it does not actually thin the blood. It alters certain chemicals in the blood to stop clots forming so easily. This prevents a DVT from getting bigger, and prevents any new clots from forming. Warfarin is the usual anticoagulant. However, it takes a few days for warfarin tablets to work fully. So, heparin injections are often used in the first few days for immediate effect. A serious embolus is rare if you start anticoagulation treatment early after a DVT.
The aim is to get the dose of warfarin just right so the blood will not clot easily, but not too much which may cause bleeding problems. You will need regular blood tests whilst you take warfarin. You need them quite often at first, but then less frequently once the correct dose is found. (If you are pregnant, regular heparin injections rather than warfarin tablets may be used.)
Compression and raising the leg -
to prevent post-thrombotic syndrome
If the DVT was in a thigh vein, you may be advised to wear a compression stocking. With this treatment the risk of developing post-thrombotic syndrome is much reduced. You should wear the stocking each day, for at least 2 years. (Symptoms of post-thrombotic syndrome may develop even several months after a DVT, which is why you should wear the stocking long-term.)
The slight pressure from the stocking helps to prevent fluid seeping into the calf tissues from the outer veins which carry the extra diverted blood following a DVT. The stocking also reduces, and may prevent, calf swelling. This in turn reduces discomfort and the risk of skin ulcers forming.
If you are advised to wear a compression stocking, you should put it on each day whilst lying in bed before getting up. Wear it for the whole day until you go to bed, or until you rest in the evening with the leg raised. Take the stocking off before going to bed.
In addition, the following are also commonly advised.
Preventing a first DVT - or a
recurrence of a DVT
A DVT is often a 'one-off' event after a major operation. In this situation you will normally be advised to stop taking warfarin after a few months. Some people have an ongoing risk of a further DVT. For example, if you have a blood clotting problem, or continued immobility. You may then be advised to continue taking warfarin long-term.
Other things that may help to prevent a first or recurrent DVT include the following.
See your physician if you suspect you have poor leg circulation, as the condition can be serious and an indication of another medical problem. Medications are available to treat leg circulation problems and to help prevent more serious consequences.