Are varicose veins linked to deep vein thrombosis?
28th February 2018 – Having varicose veins may increase the risk of a potentially serious condition known as deep vein thrombosis (DVT), a new study suggests.
According to the National Institute for Health and Care Excellence (NICE) at least a third of the UK population have varicose veins, and women are more likely than men to develop them.
Blood flow problem
They are easily recognised as bulging, knotty, purple or blue veins that are most commonly seen in the legs.
Varicose veins develop when tiny valves inside a vein stop working properly, causing pooling of blood in the veins.
They may cause discomfort, but they have rarely been associated with any other serious health condition.
However, Taiwanese researchers say they found that people with varicose veins had a 5.3-fold higher risk of deep vein thrombosis than those without varicose veins.
DVT is a blood clot in one of the body's deep veins, usually in the legs. It affects around 1 in 1,000 people in the UK each year.
If a blood clot breaks free and travels to the lungs, it is called a pulmonary embolism, which can be fatal.
The latest study, published in the Journal of the American Medical Association (JAMA) involved 425,968 Taiwanese adults over the age of 20 with and without varicose veins who were followed up for an average of 7-and-a-half years.
The authors say their findings support a number of previous studies, including German research that found a 7-fold higher rate of DVT among people with varicose veins than those without the condition.
They suggest one possible explanation is that people with varicose veins have increased levels of inflammation or blood clotting abnormalities.
However, they say the observational nature of their research means they cannot prove cause and effect. They say further research is needed to determine whether varicose veins can cause DVT or whether they simply share similar risk factors.
The study did not find any links between varicose veins and two other vascular diseases, pulmonary embolism (PE) and peripheral artery disease (PAD).
In an emailed comment, Chris Allen, senior cardiac nurse at the British Heart Foundation, says: "We currently do not know a great deal about the links between varicose veins and other serious conditions. However, we may need to be more conscious of a potentially higher risk of deep vein thrombosis in people who have varicose veins."
He adds: "As the researchers have suggested, we need more research to understand how these conditions are linked to enable us to understand different individual levels of risk more thoroughly."