Deep vein thrombosis

What is deep vein thrombosis?

Deep vein thrombosis also called DVT for short occurs when a blood clot forms in a major vein, usually in the legs and/or pelvis (lower abdomen). The clot, which is produced when blood turns from a liquid to a solid state, forms in veins where blood flow is slow or has been disturbed. The clot may block blood flow from the legs back to the heart, or a piece of the clot may be carried back through the heart and then lodge in a blood vessel, blocking its flow. Blood clots that travel to the lungs can affect the lungs ability to take in oxygen, this is called a pulmonary embolism and it can be fatal. However, it is possible to have a small deep vein thrombosis that won't be fatal or cause symptoms.

Deep vein thrombosis is quite rare and is most likely to occur after an operation or after long periods of inactivity. Hence the recent publicity about DVT and long haul flights.

What causes deep vein thrombosis?

People with a condition that causes blood thickening have the highest risk of developing deep vein thrombosis, these risk factors could include any of the following :

• People who have recently had major surgery, especially on their legs, hips or knees.
• People who are bedridden.
• People who smoke.
• People who are overweight.
• People with badly broken leg bones.
• If you have Hughes Syndrome.
• If you are pregnant.
• If you are are over 40 years of age.
• If you use oral contraceptives or are on hormone replacement therapy (HRT).
• If you or a family member have previously had deep vein thrombosis.

Why is deep vein thrombosis linked to long haul flights?

Deep vein thrombosis occurs when flying long distance because you are sat down for long periods of time with limited opportunities to move around. You are also more likely to become dehydrated, dehydration can cause the blood to become thicker than usual. Deep vein thrombosis is often referred to as Economy Class Syndrome, this is incorrect as people sat in first class are equally at risk. Deep vein thrombosis can happen in other types of long journeys as well. When flying you should follow these guidelines set by British Airways:

• Drink plenty of non-alcoholic fluids.
• Avoid drinking alcohol and drinks with caffeine, such as tea and coffee.
• Avoid smoking.
• Stand up in your seat area and stretch your arms and legs.
• Get up and move around as often as you can (at least twice an hour).
• When sitting try moving your ankles around and going up and down on your tiptoes.
• Avoid sitting with your legs crossed.
• Avoid wearing tight clothes especially, socks or tights that are too restrictive.
• Seek medical advice before travelling, if you have a previous history of deep vein thrombosis or you believe you might be at risk.

If you are at risk of deep vein thrombosis some doctors recommend you take an aspirin before you fly. This makes the blood less sticky and reduces the tendency for it to clot. You should also consider wearing low compression socks, Scholl™ have recently launched special socks aimed at preventing deep vein thrombosis.

What are the symptoms of deep vein thrombosis?

Deep vein thrombosis can occur without any symptoms. If symptoms are present you may notice your leg is swollen, painful and it may feel warm to the touch. The skin on the affected area may change colour and appear faint blue or red. You might also develop a sudden cough and a temperature.

Deep vein thrombosis usually occurs in the lower legs. If a pulmonary embolism occurs symptoms may include shortness of breath and chest pains.

Can I do anything to prevent getting deep vein thrombosis?

To avoid getting deep vein thrombosis you should keep your weight down, avoid smoking and keep active. If you are over 35 and are still on the contraceptive pill, you should speak to your doctor about other forms of contraception as the risk of deep vein thrombosis increases with age.

If you are bedridden for long periods of time you should regularly flex your legs muscles, wiggle your toes and bend your ankles to keep the circulation in your legs active. If you are at risk of deep vein thrombosis you may be given drugs when having surgery to prevent the blood from thickening up.

How is deep vein thrombosis diagnosed?

Deep vein thrombosis can be difficult to detect. Your doctor may start by giving you a physical examination and he/she may need to give you a Doppler ultrasound, to measure blood flow through the veins and sometimes a venogram. A venogram is a type of x-ray which checks the flow of blood in the suspected vein.

How is deep vein thrombosis treated?

Drugs are available to either break down clots or prevent more clots from forming. On rare occasions if the drugs fail to break down the clots you may need to have it surgically removed.

If left untreated or not treated effectively deep vein thrombosis can be fatal.

Related topics