For many Indians, flying has become almost routine, whether heading overseas for work, studying in another country, or simply visiting family.
What often goes unnoticed, though, is a health risk that travels with us. Deep vein thrombosis, or DVT, can develop when a person sits still for too long on a flight. If brushed aside, this clotting problem can grow into something far more serious.
What is Deep Vein Thrombosis?
DVT refers to the formation of a blood clot in the deep veins, most often in the legs. These veins are critical for carrying blood back to the heart. When mobility is restricted for extended periods, blood circulation slows, and this sluggish flow increases the likelihood of clot formation.
The real danger lies in the possibility of a clot dislodging and travelling to the lungs, leading to a pulmonary embolism. This complication can cause sudden breathlessness, chest pain, or even collapse, and requires immediate medical intervention.
Why Does Air Travel Increase the Risk?
The risk of DVT rises sharply during flights because of a combination of factors:
Prolonged sitting: Limited space, especially in economy seating, reduces opportunities to move or stretch.
Dehydration: Cabin air is dry, and many passengers drink less water than they need, which can cause the blood to thicken.
Restricted posture: Tight clothing, alcohol intake, or sleeping in a fixed position can all contribute to impaired circulation.
While healthy individuals are generally at low risk, certain groups are far more vulnerable:
• Individuals with a history of DVT or clotting disorders
• Those who are overweight or obese
• Patients with varicose veins
• Individuals with cancer or those who have undergone recent surgery
• Pregnant women or women in the postpartum period
• People on hormone therapy or oral contraceptives
Why This is a Growing Issue in India
Air travel in India has taken off like never before, with millions flying long hours each year. But this growth has come at a time when more people are also struggling with health problems such as obesity, diabetes, and sedentary habits.
Put together, these changes make long flights a setting where blood clots are more likely to develop.
The overlap of rising air travel and higher prevalence of risk factors explains why vascular surgeons in India are now seeing more travel-related cases of DVT.
Recognising the Warning Signs
Timely recognition of symptoms is crucial. Warning signs of DVT include:
• Swelling in one leg, occasionally both
• Calf pain or cramping is often mistaken for muscle strain
• Warmth or redness over the affected area
DVT can also remain completely silent until a clot reaches the lungs. In some people, a clot can travel to the lungs and cause what is called a pulmonary embolism.
This may show up as sudden breathlessness, sharp chest pain, feeling faint, or even coughing up blood. When that happens, it is a medical emergency and the person must be taken to the hospital right away.
Preventive Steps for Travellers
The good news is that simple measures can significantly reduce the risk of DVT during long flights:
Move regularly: Stand, walk when possible, and do ankle or calf exercises in the seat every 30–60 minutes.
Stay hydrated: Drink water throughout the journey; avoid excessive alcohol and caffeinated drinks.
Wear comfortable clothing: Loose-fitting attire reduces restriction on circulation. Compression stockings can be helpful, particularly for those at higher risk.
Seek medical advice if at risk: Individuals with prior clotting episodes, recent surgery, or major risk factors should consult their doctor before flying. In some cases, preventive medication may be advised.
When to Seek Medical Attention
If a traveller notices calf pain, swelling, or sudden breathlessness after a flight, it is important not to ignore it. Getting checked by a doctor right away can make a big difference and help avoid serious problems.
Key Takeaway
Flying has become part and parcel of modern life, yet sitting still for too long in cramped seats carries risks we often overlook.
Deep vein thrombosis, in many cases, can be avoided if people stay alert, take simple precautions, and seek medical help without delay when warning signs show up. Recognising the link between long flights and clotting risk is the first step towards safer travel.
Disclaimer: The views expressed in this article are of the author and not of Health Dialogues. The Editorial/Content team of Health Dialogues has not contributed to the writing/editing/packaging of this article.