Why your 9-to-5 desk job could be putting you at risk of thrombosis

If your workday is anything like long hours in front of a computer, brief lunches and hardly any movement, there's a secret you should know: sitting all day may quietly be adding to your risk of getting life-threatening blood clots.

Physicians caution that too much sitting, whether at work, while traveling, or even in the home, can cause venous thromboembolism (VTE), an illness that encompasses deep vein thrombosis (DVT) and pulmonary embolism (PE). These illnesses usually don't manifest until advanced, sometimes even lethal. We reached out to Dr Sunil Rana Associate Director and Head- Internal Medicine (Unit III), Asian Hospital to understand the issue.

What is thrombosis?

Thrombosis occurs when a blood clot forms inside a vein, restricting normal blood flow. Deep vein thrombosis (DVT) usually happens in the legs. Pulmonary embolism (PE) occurs when part of that clot travels to the lungs, which can be fatal if untreated. Dr Rana shared, "The dangers of prolonged sitting are not restricted to work alone; long hours of travel or even marathon TV binge viewing can result in venous thromboembolism (VTE), a condition that includes deep vein thrombosis (DVT) and pulmonary embolism (PE). These conditions normally do not emerge until they are advanced, and in some cases they are fatal."

Why sitting increases the risk

When you spend hours sitting, blood circulation in your legs reduces. Venous stasis caused by this makes it even simpler for clots to develop, particularly if you are dehydrated, overweight, or have other medical risk factors. With time, this stagnation can cause inflammation in your blood vessels and result in clot development.

It's not only office workers in danger: long flights, car travel, and even TV marathon binges can do the same thing. Research indicates that individuals sitting for eight or more hours a day have a substantially increased risk of developing VTE.

Early warning signs of thrombosis

Blood clots may begin small and unnoticed. Dr Rana shared, "Look out for early signs like swelling in one leg (e.g., calf or thigh), pain, tenderness, or redness in the affected leg, redness or darkening of the skin, sudden shortness of breath or chest pain, rapid heartbeat or dizziness. It is important to consult a healthcare professional immediately if you experience these symptoms, especially after prolonged inactivity." Watch out for:

• Swelling in a single leg (particularly calf or thigh)
• Pain, tenderness, or redness in the problem leg
• Redness or darkening of the skin
• Sudden shortness of breath or chest pain
• Rapid heartbeat or dizziness
• If you experience these signs, especially after prolonged periods of inactivity, get medical help right away

Who is at greater risk

Although anyone can get a clot, your chances are greater if you:

• Sit for extended periods of time with no movement
• Had surgery or an injury recently
• Use birth-control pills or hormone therapy
• Smoke or are obese
• Have a family history of clots or varicose veins

How to keep yourself safe

Shift every 30–45 minutes: stand up, stretch, or take a short walk around. Even one minute of activity every half-hour improves blood flow.

• Stay hydrated: Dehydration thickens the blood, increasing clot risk. Sip water regularly throughout the day.
• Practice simple desk exercises: remember to do ankle circles, heel raises, and seated leg lifts to keep circulation active.
• Sit up straight: sit with feet flat on the floor, not crossing legs for extended periods, and back-support chair adjustment.
• Keep active outside work: include a minimum of 150 minutes of moderate physical activity each week: cycling, brisk walking, or swimming can significantly boost circulation.

Be cautious during travel: on long flights or drives, take walking breaks, flex your calves, and stay hydrated. For higher-risk individuals, compression socks can help. Dr Rana added, "With a little effort, you can reduce the risk of clot formation. Every 30-45 minutes, shift positions: stand up, stretch, or go for a short walk around. Even one minute of exercise every half hour boosts blood flow.  Stay hydrated as dehydration thickens the blood, increasing clot risk. To maintain circulation, use easy desk exercises such as ankle circles, heel raises, and sitting leg lifts. Sit up straight with feet flat on the floor, avoid crossing legs for long periods of time, and adjust the back-support chair. Include at least 150 minutes of moderate physical activity per week, such as cycling, brisk walking, or swimming, to improve circulation. Remember to take breaks during long flights or drives, flex your calf muscles and stay hydrated. High risk individuals can benefit from compression socks."

When to call a doctor

If you suddenly experience leg pain, unexplained swelling, or shortness of breath, don’t ignore it. Early diagnosis through tests like an ultrasound or D-dimer can prevent life-threatening complications.

Sitting itself isn’t the problem; sitting without movement is. Think of your body as designed for motion. Every step you take during the day reduces your risk of dangerous clots. So get up, stretch, and give your veins the workout they deserve.

Also read: Desk job and knee damage: 5 posture mistakes that secretly harm your knees