Following these simple steps – recommended by our expert – can help you avoid the hidden holiday killer disease that claims 4,000 people every year

As the country heads into the busy holiday season, the Irish Heart Foundation is urging travellers not to overlook a potentially life threatening risk: thrombosis, also known as blood clots.

Here, Dr Angie Brown, consultant cardiologist and Medical Director of the Irish Heart Foundation, explains the risks, and crucially, how to avoid them. 

Venous thrombosis, including deep vein thrombosis (DVT) and pulmonary embolism (PE), are relatively common conditions, affecting approximately 1 to 2 people per 1,000 annually in Western populations. 

About two–thirds of these cases are DVT, and one–third are PE. It is the third most common cardiovascular disease after myocardial infarction and stroke.

Around 4,000 people die of thrombosis related deaths – venous thromboembolism or blood clots in the veins each year.

Often associated with long–haul flights and extended car journeys, venous thromboembolism (VTE) – which includes deep vein thrombosis (DVT) and pulmonary embolism (PE) – remains under–recognised, despite affecting thousands of people every year.

And while most holiday–makers focus on passports and packing, doctors are urging the public not to overlook a less obvious risk: travel related thrombosis, also known as deep vein thrombosis (DVT).

In Ireland, thrombosis is a common, yet overlooked, condition. Around 5,000 people are affected by VTE annually, with more than one in 12 people expected to experience a clot during their lifetime.

Blood clots form when blood flow slows, often during periods of prolonged immobility.

Risk increases sharply with age and in certain medical conditions. 

Risk factors include being over the age of 60, obesity, pregnancy or recent childbirth, use of oestrogen containing contraception or hormone replacement therapy, cancer, previous clots, thrombophilia, recent surgery, or limited mobility.

Long distance travel can also increase the risk, particularly when journeys exceed four to six hours, whether by air, car, train or ferry.

Despite this, awareness remains low.

According to the HSE, 75% of adults have never heard of DVT, and fewer than one in ten can identify its symptoms.

Awareness is crucial – especially ahead of the busy holiday season.

Thrombosis is often underestimated because it doesn’t always cause symptoms until it becomes serious.

Yet it is one of the most preventable causes of death and disability if people understand the risks and take simple precautions.

People often associate clots with aeroplanes, but we see can them after long car trips or ferry journeys as well as long stays in hospital.

It’s immobility – not the destination – that’s the issue. Preventing thrombosis during travel is largely about keeping blood moving.

People often associate blood clots with serious illness or surgery, but prolonged sitting during travel is a well recognised trigger.

The good news is that many travel related clots are preventable with simple measures.

Keep Moving

Stand, stretch or walk every 1–2 hours wherever possible. Even simple in–seat exercises—like ankle rotations or calf raises—can help maintain circulation. Also, avoid crossing your legs for long periods.

Stay Hydrated

Dehydration can thicken the blood, increasing clot risk. Drink water regularly and limit alcohol or caffeine on long journeys.

Wear Compression Stockings IF REQUIRED

For higher–risk individuals, properly fitted compression socks can significantly improve circulation and reduce the likelihood of clot formation.

Choose Your Seat Wisely

An aisle seat makes it easier to get up and move, which can help lower risk.

Know Your Personal Risk

For example if you’ve had a clot before, or you’ve been in hospital and had recent surgery, or have active cancer, it’s essential to speak to your GP before you travel. In some cases, preventative medication may be recommended.

Know the Warning Signs:

Being able to recognise symptoms early can save lives.

Common signs of DVT include swelling in one leg, pain, tenderness, or warmth in one calf and red or discoloured skin.

Pulmonary embolism symptoms—requiring urgent medical attention—include: Sudden shortness of breath, chest pain particularly on breathing, rapid heartbeat and coughing up blood.

A Preventable Risk

Thrombosis is a leading but preventable cause of illness and death. Many cases—especially those linked to travel—can be avoided with awareness and simple steps,

Travel should be enjoyable, not dangerous.

The key message is simple—move often, stay hydrated, and know your risk.

These small actions can make a life–saving difference. And if symptoms appear during or after travel, people should seek medical help urgently. Early treatment saves lives.

Consultant cardiologist and Medical Director of the Irish Heart Foundation