Avoiding Fatal Blood Clots on Long-Haul Flights
Blood clots are a serious risk for travelers, particularly during and following a long-haul flight. TPG Contributor Christine Cantera speaks to a physician to determine which steps you should take to stay healthy while on the road.
Health issues that arise from traveling have long been a worry for frequent flyers, so we wanted to let our readers know more about pulmonary emboli — otherwise known as blood clots — and offer some preventive advice.
According to the UpToDate® evidence-based clinical decision support resource, deep vein thrombosis (DVT) is the most common type of thrombosis, occurring in the "deep veins" in the legs, thighs or pelvis. If a part or all of the blood clot in the vein breaks off, it can travel through the venous system; this is called an embolus. If the embolus lodges in the lung, it is called pulmonary embolism (PE), a serious condition that leads to over 50,000 deaths a year in the United States. In most cases, PE is caused when part of a DVT breaks off and lodges in the lung.
We asked Dr. John Silbert, a San Diego-based family practitioner for more than 30 years who has cared for many patients with DVT and pulmonary emboli, if he could shed some light on exactly how these conditions happen, and if they can be prevented. (Full disclosure: Dr. Silbert is the father of TPG Copy Editor/Contributor Sarah Silbert.)
"Older people are at higher risk, but younger people are also affected," explains Dr. Silbert. "Most of the time, DVT and pulmonary emboli are acquired conditions, though family history and genetic inheritance often contribute." In fact, Silbert emphasized that they're often related to a patient's personal medical history.
Specifically, a high percentage of DVT and PE cases are associated with the person having been hospitalized within the previous three months. People who are at particular risk include those who've had recent surgery or trauma; are obese; smoke; have cancer; have heart problems; have other chronic diseases including collagen-vascular disease and myeloproliferative disease; women who are pregnant or have been recently pregnant, taking hormone replacement therapies, or on birth control pills; and anyone with kidney disease. Genetic problems can include several disorders related to coagulation, including Factor V Leiden, deficiencies of natural proteins that prevent clotting (e.g., antithrombin, protein C or protein S).
"The key is having the diagnosis of DVT made early enough that treatment can be started to prevent pulmonary embolism from occurring. PE will occur in about 50% of untreated people, usually within days or weeks of the DVT. If it goes untreated there is an overall mortality rate from PE of up to 30%, but much lower when treated. The worst thing that can happen is that you don't get to the clot in time and it travels to the lung", Dr. Silbert explained."DVT and pulmonary emboli have less to do with frequent travel and more to do with the person's health and habits and what was happening within a few months before traveling. The real sorrow is that so many potentially treatable DVT and pulmonary emboli still go undetected."
On that note, all travelers should consider the following recommendations for flights longer than six hours:
- Stand up and walk around every hour or two
- Wear loose-fitting, comfortable clothing
- Flex and extend the ankles and knees periodically, avoid crossing the legs, and change positions frequently while seated
- Consider wearing knee-high compression stockings
- Avoid medications (e.g., sedatives, sleeping pills) or alcohol, which could impair your ability to get up and move around
Be sure to stay aware and listen to your body, and especially if you've been treated for any kind of illness within three months of your journey, follow these instructions to the letter — and above all, travel safe.
Update: Emergency physician Alan Cherney wrote in to share symptoms of DVT and PE. If you experience any of the symptoms below, seek medical assistance immediately.
Signs and symptoms of DVT include pain in the lower extremity, often the calf; redness of the lower extremity; swelling of the calf or lower extremity; difficulty ambulating on the affected lower extremity; swelling of the superficial veins. Signs and symptoms of a PE include chest pain or discomfort; shortness of breath at rest or on exertion; pain with deep inspiration/breathing; palpitations or rapid heart rate; sudden loss of consciousness; coughing up blood; fatigue.
TPG featured card
at American Express's secure site
Terms & restrictions apply. See rates & fees.
| 3X | Earn 3X Miles on Delta purchases. |
| 1X | Earn 1X Miles on all other eligible purchases. |
Pros
- Delta SkyClub access when flying Delta
- Annual companion ticket for travel on Delta (upon renewal)
- Ability to earn MQDs through spending
- Various statement credits for eligible purchases
Cons
- Steep annual fee of $650
- Other Delta cobranded cards offer superior earning categories
- Earn 100,000 Bonus Miles after you spend $6,000 or more in purchases with your new Card within the first 6 months of Card Membership and an additional 25,000 bonus miles after you make an additional $3,000 in purchases on the Card within your first 6 months, starting from the date that your account is opened. Offer Ends 04/01/2026.
- Delta SkyMiles® Reserve American Express Card Members receive 15 Visits per Medallion® Year to the Delta Sky Club® when flying Delta and can unlock an unlimited number of Visits after spending $75,000 in purchases on your Card in a calendar year. Plus, you’ll receive four One-Time Guest Passes each Medallion Year so you can share the experience with family and friends when traveling Delta together.
- Enjoy complimentary access to The Centurion® Lounge in the U.S. and select international locations (as set forth on the Centurion Lounge Website), Sidecar by The Centurion® Lounge in the U.S. (see the Centurion Lounge Website for more information on Sidecar by The Centurion® Lounge availability), and Escape Lounges when flying on a Delta flight booked with the Delta SkyMiles® Reserve American Express Card. § To access Sidecar by The Centurion® Lounge, Card Members must arrive within 90 minutes of their departing flight (including layovers). To access The Centurion® Lounge, Card Members must arrive within 3 hours of their departing flight. Effective July 8, 2026, during a layover, Card Members must arrive within 5 hours of the connecting flight.
- Receive $2,500 Medallion® Qualification Dollars with MQD Headstart each Medallion Qualification Year and earn $1 MQD for each $10 in purchases on your Delta SkyMiles® Reserve American Express Card with MQD Boost to get closer to Status next Medallion Year.
- Enjoy a Companion Certificate on a Delta First, Delta Comfort, or Delta Main round-trip flight to select destinations each year after renewal of your Card. The Companion Certificate requires payment of government-imposed taxes and fees of between $22 and $250 (for itineraries with up to four flight segments). Baggage charges and other restrictions apply. Delta Basic experiences are not eligible for this benefit.
- $240 Resy Credit: When you use your Delta SkyMiles® Reserve American Express Card for eligible purchases with U.S. Resy restaurants, you can earn up to $20 each month in statement credits. Enrollment required.
- $120 Rideshare Credit: Earn up to $10 back in statement credits each month after you use your Delta SkyMiles® Reserve American Express Card to pay for U.S. rideshare purchases with select providers. Enrollment required.
- Delta SkyMiles® Reserve American Express Card Members get 15% off when using miles to book Award Travel on Delta flights through delta.com and the Fly Delta app. Discount not applicable to partner-operated flights or to taxes and fees.
- With your Delta SkyMiles® Reserve American Express Card, receive upgrade priority over others with the same Medallion tier, product and fare experience purchased, and Million Miler milestone when you fly with Delta.
- Earn 3X Miles on Delta purchases and earn 1X Miles on all other eligible purchases.
- No Foreign Transaction Fees. Enjoy international travel without additional fees on purchases made abroad.
- $650 Annual Fee.
- Apply with confidence. Know if you're approved for a Card with no impact to your credit score. If you're approved and you choose to accept this Card, your credit score may be impacted.
- Terms Apply.
- See Rates & Fees