Obesity has more than doubled since 1980 worldwide. The number of deep-vein clots is rising right along with that.
Doctors aren't yet sure exactly why, but people who have a body mass index of at least 30 are more likely than people of normal weight to get a blood clot deep in a vein, called deep vein thrombosis, or DVT.
DVT is a blood clot that forms deep in your veins, most often in your leg. It can partially or completely block blood flow back to the heart and damage the one-way valves in your veins. It can also break free and travel to major organs, such as your lungs, which can be very dangerous. About 1 in 10 people die from DVT complications.
About 350,000 Americans are diagnosed with these blood clots each year, and almost as many have them and don't know it. Even if you're at risk, you can take steps...
People who are obese tend to have a less active lifestyle. Being idle makes your blood flow sluggish, and this makes clots more likely.
Extra fat around your belly will also stop blood from moving easily through the deep veins.
Obesity changes the chemical makeup of blood, and it leads to inflammation. Both make your blood more prone to clotting.
And obesity puts you at risk for diabetes, which boosts your chances for getting DVT, too.
What You Can Do
Studies show that losing weight can change your blood chemistry and lower your risks. Overweight and obese adults who did moderately intense aerobic exercise improved their blood health, even if they didn't lose weight.
Unfortunately, it doesn't look like you can lower the risk of a second DVT by losing weight after you've had one.
A lot of fish with omega-3 fatty acids in your diet may help protect your blood against abnormal clotting. Avoid high-carb diets -- they can make your blood more likely to clot.
Your doctor can and should help you get from obese to a healthy weight.