Am I at Risk for a Blood Clot?

9 Hidden Dangers of Blot Clots
All Rights Reserved

Did you know that after a serious injury or hospitalization, the risk of a life-threatening blood clot is hugely increased? Probably not -- chances are, you don't think much about blood clots at all. (Except when you have a cut and want it to heal, of course.)

Unfortunately, when a clot forms in your legs, feet, groin, or a major vein, a condition known as deep vein thrombosis (DVT), it can take almost no time for it to travel to your lungs, cutting off your breathing. This is known as a pulmonary embolism, and it is potentially fatal. In fact, hospital admissions -- and deaths -- from blood clots are much more common than most of us realize.

While statistics vary according to the type of data used, one study cited by the National Blood Clot Alliance ( found that more than 2 million people have a serious blood clot emergency each year. Deaths from blood clots may top 100,000 a year, which would make blood clots the third-highest cause of death following heart disease and cancer. Needless to say, it's important to know when your risk of a blood clot is highest, and the signs to be on the lookout for.

Here are 9 reasons you might be in greater-than-average danger of suffering a blood clot emergency, and ways to reduce that risk.

1. You're Overweight or Obese

Carrying extra weight increases the pressure on the veins in your feet and legs, weakening veins and causing swelling and circulation issues that increase the risk of deep vein thrombosis (DVT) and pulmonary embolism (PE), which together are known as venous thromboembolism.

What to do: Losing weight is important as a long-term goal; in the meantime, you can help increase circulation and reduce pressure by getting more exercise and stretching out foot and calf muscles. Wearing graduated compression stockings or socks can also help prevent swelling, circulation problems, and clots.

Note: No matter what your risk level, if you do experience symptoms of a pulmonary embolism, such as unusual shortness of breath, sharp chest pain, an elevated heart rate, or a cough that's bloody, call your doctor right away or go to the emergency room. Early warning signs of DVT include swelling, pain, or warmth in your legs or groin area, and this is also a reason to call your doctor right away.

2. You're on Birth Control Pills or Take Hormone Therapy

Estrogen, the primary hormone in birth control pills and hormone therapy, is known to increase clotting factors in your blood. The risk of this happening increases greatly if you're overweight or you smoke.

What to do: Take the risk of venous thromboembolism into account in making decisions about birth control pills and hormone therapy, particularly if you have other risk factors. For example, many doctors advise women who smoke against taking hormones.

3. Your Family History Includes Blood Clots

A number of genetic factors can cause abnormalities in blood clots, and they're more common than many people realize. For example, one such factor, V Leiden, affects 5 to 7 percent of people of white European descent. Some studies have also shown that people with AB type blood have a higher clot risk than those with type O blood.

What to do: If a member of your immediate family develops DVT or PE, bring this to the attention of your doctor. Then talk to family members to find out if there are other instances of abnormal clotting so you have as complete a family history as possible. Genetic medicine is a growing field, and your doctor may recommend genetic testing if there is reason to suspect a significant risk.

4. An Illness or Injury Has You on Bed Rest

Lying prone for long periods of time with your legs elevated allows blood to pool in your veins, increasing the risk of DVT. Remaining still also increases clot risk because you need muscle contractions in your legs to keep circulation moving.

What to do:
If permitted, move your legs around in bed, raising your knees and clenching and unclenching your muscles. Even better, get out of bed and move around every few hours, or at least swing your legs over the bed and move them. If you're immobilized by a broken bone or other injury, talk to your doctor about what physical actions you can take to reduce clot risk. Blood-thinning medications can also help those on bed rest.

5. You're a Traveler

While you might have heard that plane travel raises the risk of blood clots, you probably don't think about this issue when it comes to long car rides, or when you're on a bus or train. But of course you can be just as confined in a car, bus, or train as you are on a plane. Being cramped in a small space keeps your muscles from doing their job of stimulating circulation and can also cause swelling in your feet and ankles that further impacts clotting.

What to do: Your goal is to not remain cooped up in a sitting position for more than four hours at a time, so take breaks to move around whenever possible. On plane, bus, and train trips, stand up and walk up and down the aisles. Break up long drives with stops that allow you to move, not sit. Bring food with you or pick up a sandwich at a deli so you can picnic in a park or stroll around town rather than sitting in a restaurant to eat. If other conditions put you at particular risk for blood clots, your doctor may advise wearing graduated compression socks or stockings on long trips.

6. You're Having Surgery

When veins are injured or cut, as occurs during surgery, clots can form during the healing process. The risk of clots increases with the length of time you're unconscious as a result of anesthesia.

Knee or hip replacement surgery is even more of a risk factor because the process of preparing the bones for the artificial joints can release tissue into the bloodstream, contributing to a clot. There's also the fact that the prolonged recovery from joint replacement surgery means you're immobile for a long period of time.

What to do: Talk to your doctor about clot risk. In many cases, you'll receive blood-thinning medication before and after surgery that can help prevent the development of clots.

7. You Smoke

Cigarette smoking ups blood clot risk by affecting both circulation and the clotting process itself.

What to do: Sorry, but the advice on this one is pretty clear -- quit. If you're ready to quit but can't seem to do it, try these 10 quit-smoking tips.

8. You're Pregnant or Just Had a Baby

Like being overweight, pregnancy puts increasing pressure on the veins in your pelvis and legs, weakening them and upping the risk of DVT and PE. Blood clots also pose a risk to your baby, because they can lodge in the placenta, cutting off blood supply.

What to do:
Your doctor will evaluate your blood clot risk based on other factors, such as family history or being overweight, and will monitor you carefully, prescribing anticoagulant medication if necessary. Staying active during your pregnancy can help prevent blood clots. You should also be on the alert for signs of DVT such as swelling and pain in your legs, and talk to your doctor if you experience warning signals. The increased risk of a blood clot continues for up to two months after your baby is born, so stay on the alert until you're given the all-clear.

9. You're a Cancer Survivor

Cancer raises your risk of DVT and PE in a number of ways. Certain cancers, including lung, ovarian, and pancreatic tumors, release substances that make the blood clot more easily. Some medications used to treat cancer, including some chemotherapy agents and the hormonal therapy drugs tamoxifen and raloxifene, also raise clotting risk.

What to do:
If you're being treated for cancer, talk to your doctor about blood clots and ask if your particular type of cancer or medication regimen puts you at risk for DVT or PE. If you've been treated for cancer in the past, particularly breast cancer, it's also a good idea to talk to your doctor, as the elevated risk of blood clots can persist for years after treatment.

Melanie Haiken

Melanie Haiken discovered how important it is to provide accurate, targeted, usable health information to people facing difficult decisions when she was health editor of Parenting magazine. See full bio