Blood Clots: What Causes Them and How to Prevent Them

Blood clots can change your life fast. Some start in the legs (deep vein thrombosis) and others travel to the lungs (pulmonary embolism). Spotting risk factors and acting quickly can stop a small problem from becoming an emergency.

Common risk factors include recent surgery, long travel, cancer, hormone therapy, pregnancy, obesity, smoking and inherited clotting problems. Age also increases risk. If any of those apply to you, mention them to your doctor so they can decide if tests or preventive steps are needed.

Spotting symptoms early

Watch for swelling, pain, warmth or redness in one leg. Sudden shortness of breath, chest pain, lightheadedness or coughing up blood are red flags for a pulmonary embolism. Call emergency services if you get these symptoms.

Clots can also be silent. If you've had surgery, a long flight or have known risks, ask about D-dimer blood tests or a leg ultrasound to check for hidden clots.

Prevention and everyday steps

Move regularly. Stand and walk every hour on long trips or during long stretches at a desk. Wear loose clothing for flights and try compression stockings if a clinician recommends them. Drink enough water and avoid heavy alcohol before long travel.

If you smoke, quitting lowers clot risk. Losing weight and staying active help too. If you use birth control or hormone therapy, talk with your provider about options that reduce clot risk when needed.

If you already take blood thinners like warfarin (Coumadin) or antiplatelet drugs such as clopidogrel (Plavix), follow dosing and monitoring instructions closely. Warfarin needs regular INR checks and steady vitamin K from foods like leafy greens. Plavix has fewer food rules but still needs medical oversight.

Never stop or change doses without talking to your clinician. Stopping anticoagulants suddenly can let clots form again. Before surgery, ask when to pause medications and whether a short-term bridge with another drug is needed.

Know bleeding signs while on blood thinners: unusual bruising, blood in urine or stool, long bleeding from cuts, or severe headaches. Report these to your doctor right away.

There are newer anticoagulants that often need less routine monitoring than warfarin. Your clinician will weigh kidney function, other drugs and bleeding risk to pick the best option for you.

Finally, keep an updated medication list and wear medical ID if you take long-term anticoagulants. That helps emergency teams treat you faster and safer.

If you travel, pack your meds in carry-on with a copy of the prescription and a brief note from your doctor. Avoid starting supplements like high-dose omega-3s or over-the-counter NSAIDs without checking - they can affect bleeding risk. Low molecular weight heparin (LMWH) is often used around surgery or during pregnancy because it's safer for the baby than warfarin. Aspirin may help some people but isn't right for everyone. Talk to your pharmacist about drug interactions and carry clear instructions for emergencies so first responders know your clot and bleeding risks and allergies.

Blood clots are preventable in many cases. Know your risks, move regularly and work with your healthcare team on a prevention or treatment plan that fits your situation.