Health Library







Categories > Blood Disorders >

Flight plan
Why clots happen
Flight-safety tips
Warning signs


Postpone your trip?
Postpone your trip?

You’ll need to avoid air travel if you:

  • had a heart attack in the past two weeks
  • had angioplasty or a stent placed in the past two weeks
  • had bypass surgery in the past three weeks
  • have unstable angina, poorly controlled heart failure or an uncontrolled arrhythmia

You’ve decided to take a European vacation, but you’ve heard long plane flights may put you at risk for blood clots in the legs. Should you take extra precautions?

Experts say most people, even those with cardiovascular disease, can travel safely on airplanes as long as they follow certain guidelines.

Why clots happen

The problem with air travel begins with sitting inactive for long periods, especially for more than six hours. Such inactivity decreases circulation, allowing blood to pool and clot in your veins, causing thrombosis, a potentially fatal condition. Plus, flying at an altitude with reduced oxygen can also contribute to clots. Some people have factors that increase their risk, such as having varicose veins, a pacemaker or catheter, a history of stroke and some cancers or a family history of blood clots. Women who are pregnant, recently gave birth or use hormone replacement therapy are more susceptible, too.

Flight-safety tips

You can avoid thrombosis by taking some simple precautions:

  • Don’t wear restrictive clothing around your waist and legs.
  • Drink plenty of water and avoid caffeine and alcohol.
  • Request an aisle seat so you can get up and walk around more easily during the flight. Stretch your calf muscles frequently.
  • Wear below-the-knee compression stockings during the flight.

If you already have a heart condition, be sure to:

  • Run your plans by your doctor, who may order tests to confirm your condition is stable or prescribe an antiplatelet medication.
  • Pack adequate supplies of your medication in your carry-on bag.
  • Carry a copy of your medical history, including your latest electrocardiogram.
  • Carry contact information for your doctors, family members and your pacemaker or implanted defibrillator manufacturers.

Warning signs

Blood clots typically form in the legs, and the affected vein may be near the surface (superficial thrombosis) or deep within a muscle (deep vein thrombosis). With a superficial clot, you may have a red, hard and tender cord just under your skin. When a deep vein is affected, your leg may become painful and swollen and you may have a fever. If you develop these symptoms, seek medical attention right away.