How Sitting Too Long Can Turn Deadly | World Thrombosis Day 2025
Sitting through long flights, long drives, or working at a desk for hours without moving can slow blood flow in the legs, causing Thrombosis.
Published : October 13, 2025 at 11:06 AM IST
Today, October 13, is World Thrombosis Day — a day that draws attention to one of the world’s most under-recognised but deadly health risks: blood clots. They sound harmless, but blood clots are behind one in every four deaths globally, according to the International Society on Thrombosis and Haemostasis (ISTH). That’s more deaths than from AIDS, breast cancer, and car crashes combined. The scary part is that most people don’t even know they’re at risk until it’s too late.
What Exactly Is Thrombosis?
Thrombosis happens when blood clots form in your veins or arteries and block normal blood flow. These clots can show up anywhere in the body, but when they form deep inside the veins (usually in the legs), it’s called Deep Vein Thrombosis (DVT). If a piece of that clot breaks off and travels to the lungs, it causes a pulmonary embolism (PE), a potentially fatal blockage.
Together, DVT and PE are known as Venous Thromboembolism (VTE): a serious, sometimes sudden condition that kills millions each year. According to global estimates, about 10 million people are affected by VTE every year. In India, it’s often underdiagnosed or mistaken for other conditions like muscle pain or swelling. Hospital studies suggest that 1 in 3 patients admitted for major surgery or long-term illness may be at risk of developing DVT. About one in three people with an untreated PE don’t survive.
Why Is DVT So Dangerous?
The tricky thing about DVT is that it doesn’t always announce itself. You can feel perfectly fine one moment and suddenly develop pain or swelling in one leg the next. If the clot travels to your lungs, symptoms like sudden breathlessness, chest pain, or coughing up blood can appear without warning; and these can be deadly within minutes. Many victims of DVT-related complications don’t even make it to the hospital in time.
Warning Signs Of A Blood Clot
Blood clots can form in different parts of your body, and the symptoms depend on where they develop and how serious they are. Two of the most common and dangerous types are Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE).
Common symptoms of DVT
- Pain or tenderness: It often starts in the calf and may feel like a cramp or soreness. If the clot is in your arm, you may feel pain in the arm or shoulder area.
- Swelling: The leg (or sometimes the ankle or foot) may look puffed up or tight.
- Warmth: The affected area may feel unusually warm to the touch.
- Redness or discolouration: The skin over the area might turn red or bluish.
These symptoms don’t always show up together, but even one or two of them are enough reason to get checked immediately.
Symptoms of Pulmonary Embolism (PE)
A pulmonary embolism happens when a blood clot breaks loose and travels to the lungs, blocking blood flow. This is a medical emergency and can be life-threatening if not treated quickly.
Watch out for these symptoms:
- Shortness of breath: You suddenly find it hard to breathe, even when resting.
- Rapid breathing: You may feel like you can’t catch your breath or that your breathing has become fast and shallow.
- Chest pain: The pain may feel sharp and worsen when you take deep breaths. Any unexplained chest pain should be treated seriously.
- Lightheadedness or fainting: Feeling dizzy or actually passing out can be a sign that a clot has reached your lungs.
- Coughing up blood: If you see blood when coughing, seek emergency medical help right away.
If you experience any of the above symptoms, even mildly, contact a healthcare provider immediately.
References:
- https://www.ncbi.nlm.nih.gov/books/NBK507708/
- https://www.ahajournals.org/doi/10.1161/ATVBAHA.124.320151
- https://pubmed.ncbi.nlm.nih.gov/33984268/
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