How to recognise symptoms of thrombosis

You might not know it, but thrombosis is linked to a quarter of all deaths worldwide, as the root cause of heart disease, ischaemic stroke and venous thromboembolism.

But how much do you know about this condition, and are there things we can do to prevent it?

We take a look at some of the key questions about thrombosis, and get advice from Dr Salim Shafeek, a consultant haematologist at The Priory Hospital  and The Droitwich Spa Hospital.

What is thrombosis?

Most of us have probably heard of deep vein thrombosis (DVT) – which is the reason we’re advised to move and stretch regularly on long haul flights. This is a condition that affects about five people in every thousand, and it’s where a blood clot develops within a deep vein in the body – most commonly in your leg.

However, thrombosis is a broader term referring to any blood clot in your circulatory system, and when we talk about thrombosis we typically mean that blood clots have come to block veins or arteries. It becomes more common once we reach the age of 40.

There are two main types of thrombosis: venous thromboembolism (VTE), which is a blood clot that develops in a vein, and arterial thrombosis (AT), which is a blood clot that develops in an artery. DVT is a type of venous thromboembolism.

What causes thrombosis?

There are a number factors that can increase your risk, including:

• Very long periods of inactivity
• A family history of related conditions
• Taking the contraceptive pill
• Damaged blood vessels (i.e. from surgery or inflammation)
• Pregnancy (this varies depending on a woman’s age, weight and number of previous pregnancies, but the higher risk remains for at least six weeks after giving birth)

Dr Shafeek explains: “Anyone can be affected by blood clots, although it is more common in adults over 40 years old. As well as age, a number of other factors make developing blood clots more likely. They include your family history, being inactive for long periods of time, having damaged blood vessels as a result of infection, surgery or inflammation, having an increased tendency for the blood to clot due to certain medical conditions or taking the contraceptive pill.

“Going into hospital is the biggest risk factor for blood clots in a vein. Although being in an aeroplane is often considered the major cause of deep vein thrombosis (DVT), two thirds of blood clots actually happen in hospital.

“Pregnant woman also have an increased risk of developing a blood clot in a vein, depending on their age, weight and number of previous pregnancies. This risk continues for at least six weeks after giving birth.”

What are the symptoms of thrombosis

Spotting the signs of thrombosis early is crucial to getting effective treatment. The following symptoms are indicators that you should visit your doctor:

• Swelling in the legs
• Pain or discomfort in the calves
• Redness or tenderness in the calves
• Change in temperature or colour in the legs (this can happen if blood vessels are blocked and blood is diverted to our veins)

How to reduce the risk of thrombosis

“Blood clots can be treated if they are spotted in time,” says Mr Shafeek. “However, preventing them from happening in the first place is often the preferred approach.”

In the long term, there are plenty of things you can do every day to lower your risk of thrombosis:

• Exercise more: walking, running, cycling, swimming – anything that gets the blood flowing and the heart pumping
• Stretch more: with regular exercise, stretching will improve your circulation and lower the risk of blood clots
• Drink plenty of water: staying hydrated throughout the day will do wonders for your blood
• Eat a healthy diet: studies have found that people who eat more fruit and vegetables, and less red and processed meats, have a lower risk of thrombosis

How to reduce your risk of thrombosis on long haul flights

Contrary to popular belief, blood clots happen more in hospitals than long haul flights (see below). That said, it’s easy to prevent clots while flying, so here are some expert tips for avoiding thrombosis as you rack up those air miles:

Move and stretch regularly

No one would want you doing lunges in the aisles, but a short wander with a few stretches will keep your blood flowing healthily. Do it on your way to and from the bathroom - your joints will thank you for it when you sit back down.

Drink lots of water

Tempting as a glass of wine or beer might be, drinking less alcohol and more water as you fly is the best way to stay hydrated and lower the risk of a clot forming.

Flex

It’s not practical to get up and down all the time, so get in the habit of flexing your ankles and wrists every hour or so. Some gentle neck stretches will help too.

Can’t I just take aspirin for thrombosis?

Aspirin is proven to reduce the risk of clots in arteries, but not in veins, so it won’t solve that part of the problem. It also increases the risk of gastric bleeding, which could be very dangerous if you’re on a long haul flight.

The best - and safest - way to lower you risk of thrombosis is to stay active and hydrated.

Am I at greater risk of blood clots in a hospital?

Far more than flying, the biggest risk factor for clots in veins is going into hospital, where two thirds of all blood clots happen. In fact, without serious efforts taken to reduce these risks, it’s estimated that 20,000 people would otherwise die from blood clots in hospitals every single year.

That’s why the International Society for Thrombosis and Haemostasis (ISTH) created World Thrombosis Day. It started on October 13th in 2014, and aims to raise awareness for both the public and healthcare professionals so that more deaths from blood clots can be prevented.