Flying with Blood Thinners: What You Need to Know Before You Board

When you're on blood thinners, medications like warfarin, apixaban, or rivaroxaban that prevent dangerous clots. Also known as anticoagulants, they keep your blood flowing smoothly—but flying can change how they work in your body. Long flights increase your risk of deep vein thrombosis, a blood clot that forms in a deep vein, often in the leg, especially if you’re sitting still for hours. This isn’t just a concern for older travelers—it affects anyone on these meds, even if they feel fine.

Most people on blood thinners, medications that reduce clotting to prevent strokes, heart attacks, or pulmonary embolisms can fly safely, but only if they take simple steps. The key is movement. Get up and walk the aisle every hour. Do seated leg lifts or ankle circles if you can’t get up. Avoid crossing your legs. Wear compression socks—they help blood move back up from your feet. And don’t drink alcohol or take sleeping pills to try to sleep through the flight. Both can dehydrate you and make clots more likely.

What about your meds? Always carry your blood thinners in your carry-on. Never check them. Airlines lose bags. Cold temperatures in cargo can damage some pills. Bring your original prescription bottle with your name on it, plus a doctor’s note explaining why you need them. This helps if security asks. If you’re on warfarin, know your last INR number. Some airports have clinics where you can get a quick check if you’re worried. Don’t wait until you’re in the air to realize you forgot your dose.

There’s also the issue of diet and other drugs. If you’re on warfarin, sudden changes in vitamin K—like eating a big salad or taking a new supplement—can throw off your clotting time. Pack your usual snacks. Avoid new herbal teas or supplements you haven’t tried before. And if you’re flying internationally, check if your meds are legal in your destination country. Some countries restrict common anticoagulants.

You’re not alone in this. Thousands of people fly with blood thinners every day without issues. The goal isn’t to avoid flying—it’s to fly smart. The posts below cover real cases: what happened when someone skipped movement on a 10-hour flight, how a traveler managed their dose across time zones, why compression socks made all the difference, and what doctors say about flying after a recent clot. You’ll also find advice on what to pack in your travel kit, how to recognize early signs of a clot mid-flight, and when to call for help before you even leave the gate.