DVT prevention

Deep Vein Thrombosis (DVT) is a blood clot that forms in a deep vein, usually in the leg, and is a recognised risk on long-haul flights and extended periods of sitting. The risk increases with flight duration, age, and certain medical conditions. The good news: it's largely preventable with the right gear and habits.

Travel Gear stocks compression socks and travel health essentials for Australian travellers, shipping from our Charlestown NSW warehouse with fast delivery across Australia. If you have a history of DVT or clotting disorders, consult your doctor before long-haul travel.

DVT Prevention Essentials

Compression Socks

The most effective single item for DVT prevention on flights. Graduated compression socks apply more pressure at the ankle and less at the calf, encouraging blood to flow upward rather than pooling in the lower leg. Medical-grade compression (15–20mmHg or 20–30mmHg) is recommended for flights over 4 hours. Look for socks that reach the knee for maximum effectiveness.

Compression Sleeves

Cover the calf only, without the foot section. Useful for travellers who find full compression socks uncomfortable or who want to wear their own socks underneath. Less effective than full compression socks but better than nothing.

DVT Prevention Tips for Long-Haul Flights

• Wear graduated compression socks from boarding to landing
• Get up and walk the aisle every 1–2 hours
• Do calf raises and ankle rotations in your seat every 30 minutes
• Stay hydrated — dehydration thickens the blood and increases clot risk
• Avoid alcohol and sleeping pills, which reduce movement during sleep
• Choose an aisle seat to make it easier to get up regularly
• Avoid crossing your legs for extended periods

Frequently Asked Questions

How long does a flight need to be before DVT is a risk?

DVT risk increases significantly on flights over 4 hours. The risk roughly doubles for every 2 hours of additional flight time. Sydney to London (22+ hours) and Sydney to Los Angeles (14+ hours) are among the highest-risk routes for Australian travellers. Compression socks are recommended for any flight over 4 hours.

Do compression socks actually prevent DVT?

Yes — multiple clinical studies have shown that graduated compression socks significantly reduce the risk of DVT on long-haul flights. A 2016 Cochrane review found that travellers wearing compression socks had a substantially lower incidence of DVT compared to those who didn't. They also reduce swelling and leg fatigue, which improves comfort regardless of DVT risk.

What compression level do I need for flying?

For most healthy travellers, 15–20mmHg (Class 1) compression is sufficient for flight use. Travellers with a history of DVT, varicose veins, or clotting disorders should use 20–30mmHg (Class 2) and consult their doctor. For more on preparing for long-haul travel, see our long-haul flight essentials guide.