Am I at Risk for a Blood Clot?

9 Hidden Dangers of Blot Clots
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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

over 2 years, said...

The headline says 9 "signs" of blood clots. The subheadline says 9 "dangers" of blood clots. The contents is about risks for blood clots. Get your act together if you want me to believe you're thinking clearly about blood clots.

over 2 years, said...

Why is there never "X" amount of hidden signs of "Blood Clots" posted other then developing in the legs, grown, feet. What about the lungs, arms, etc.???????

over 2 years, said...

why does a DVT cause neuropathy in hands and feet?

over 2 years, said...

I had clots as big as jello chunks

over 2 years, said...

i have had blood clots both legs for two years, nothing moving, doctor will not allow me to take anything, Because recent studies its best not to treat, under the knees.

over 2 years, said...

Two months ago I had three consecutive surgeries on three consecutive days, with 4 days in the ICU. Three months prior I went to my doctor because of spreading pain in my leg. An ultrasound and spine X-ray revealed nothing.. Tried to get appointment with my doctor for 4 days, went to one ER and left after three hours because I couldn't get looked at or treated other than a blood draw. The next day I went to a different ER and was immediately put on IV morphine.. I am now on Eliquis which is outrageously expensive. When I go walking, I again have pain in my calf and will have an ultrasound this week. I am extremely mad at the first ER doctor. I would have thought that they are better trained to recognize a real emergency, because I was told the next day that I could have died in one more day. Going to the ER does not guarantee ER treatment .

over 2 years, said...

I experience massive blood clot in both lungs and wasn't expected to live the night. Very sudden walking in a parking lot when it happened. After many test the reason was ruled estrogen. I am on blood thinner and will be the rest of my life. This required a 7 day ICU hospital stay. Thank god for his grace that saved me

over 2 years, said...

I have had a major Blood Clot up and down my left leg......what can I do to make sure this doesn't happen again?

over 2 years, said...

Wow, no mention of taking enzyme supplements to dissolve fibrin (nattokinaise is the enzyme for this)...also proteases and another starting with serra (often sold with nattokinaise)... I pretty much 75% elim the swollen leg with a few days of protease pills (enteric coated on empty stomach) ...foot blown up like balloon, then deflated, looking like a prune)...I had scan for clot btw, negative. Do a lot of reading about this these pills work system wide, not just on your desired result. using blood thinner active cancer tumor...too much mucous in lungs (might dissolve all at once and almost drown you...happened to me)'s a big biochemical complexity and worth effort to think through. The swelling of my leg was due mostly to a broken cyst and resulting inflammation, the swelling was so bad that plasma was forced out through my skin, weeping, hives, etc. Big patch of inflamed scar tissue. This I am eliminating, slowly but steadily. Check it out and think through your own conditions...

over 2 years, said...

this tells what if you are but it does not go far enough , what are the signs that you have them the first is a little misleading

over 2 years, said...

I had a PE back in 2008. After a Minor Surgery my Blood Pressure suddenly dipped to a dangerous level. Thankful I was still in the hospital at that time. I was still sent home a few hours later. I experienced Heart Burn, Fatigue and Shortness of Breath, and when I called my doctor to discuss those symptoms he advised me to go to the hospital, where a CT Scan revealed a Clot. Thankfully, I only spent one night at the hospital and was sent home on Warfarin for 8 months. Blood Tests every 5-7 days to check my levels during that time.Diagnosed with Phactor V Leiden, I can now deal with the dangers and lead a normal life. I can not travel for more than 3 hours without taking a blood thinner shot to prevent another PE. I am happy to have the diagnosis and know there are treatments available.

over 2 years, said...

I have upcoming spinal surgery. Great timely article.

over 2 years, said...

Very good info.

over 2 years, said...

In 1979 I developed a DVT. I did'nt know it at first, I went to ER & had a smart mouth doctor. He said to me "well will give you something for pain & see what happens' I waited hours & no one came back, so I left & the next daywent to another ER. They treated me for a clot & my GYN. gave me the number of a doctor. I was put in the hospital for 5 days & put on blood thinners for 3 months. In between I had quite a few super fiscal clots. No one could figure out why. When I was 44 I had another DVT & was admitted to the hospital, they said for 5 days. Well after 4 days I had a horrible pain in my back, right side. Then I could not walk, my left leg would not move. All clots were in the left leg. They did a CT & I had developed a bleed. They gave me to much blood thinner & had to stop it. They put the Greenfield Filter in me & could not lift my leg. I could not feel it. Very slowly I did get some feeling back. I was sent to a blood doctor & he drew 9 tubes of blood. I waited 6 weeks for the results & I had Factor V. Back then which was 1998 they were just starting to learn about it. Most doctors never heard of it. My dad died at the age of 42 of a heart attack in 1975 & came from a big family. They said he must of had it also. I am the oldest of 8 & they told me let my siblings know, which I did but no one was tested. They thought it was in my head. My one sister passed from RA but had clots in both her lungs, then another sister was in the hospital & she also had clots in the lungs & they almost lost her. My youngest brother 38 suddenly passed August 2012 from 4 clots, then my only living brother developed clots in his leg & both his lungs & was in Florida, they told him one more day & he would of died. Don't mess with this, PLEASE be checked. Sorry so long. Thank You.

over 2 years, said...

I understand having Protein C causes you to produce blood clots. I never see any information on this.

over 2 years, said...

Please spread the work about FACTOR 2 MUTATION. I was diagnosed 6 years ago, with an ER visit revealing 13 clots (major one upper thigh and 2 in each lung...) Genetic testing determined FACTOR 2, which means WARFARIN for life! I believe I survived this to tell about it: that the Mutation originated in Northern Spain and that many HISPANICS may have this. I told all my relatives and had my kids tested for this GENE. My son has it, daughter doesn't and half my relatives in the country that WERE tested, have the gene also. It has altered my lifestyle but I am a true WALKING MIRACLE thanks to physicians' care in the ER. In fact, when I travel, I must go to ER's to get my INR test and I hear many doctors fight over my case, as some have learned of this newly recognized mutation and want to take part in it's treatment. Bed rest in the hospital for a month, abdominal injections (painful Lovenox) and modern medicine (weekly INR tests), Diet, travel, stress, medication all keep my "numbers" in check. Now we know WHY other relatives died from clots in the past. Please, if you are of SPANISH descent, ask your doctor to be checked for FACTOR 2 MUTATION. The ONE thing that bothers me most: limiting my leafy greens, as they contain VITAMIN K and can contribute to clotting. Small price to pay to stay alive!

over 2 years, said...

A month ago I fell with a load of materials on my shoulder. Injuring my arm shouldet. This week they found a blood clot. Blood thinners r my only hope. The use of my arm is terrible. Almost none. Scared and confused.

over 2 years, said...

While the authors credentials guarantee necessary writing skills and her personal life involves caring for close family members who have complicated needs, this does not qualify the quality of this article related to coagulation, aggregates, thrombus or emboli. Quite a few "not quite right" statements that a lay person could not discern (one way or the other the) validity of. The "not quite right" is obvious to those of us in the science and art of physical processes that impede health.

over 2 years, said...

A very useful article which I can well relate to

over 2 years, said...

Whoops! That should have said blood THINNING medication!

over 2 years, said...

I have had a DVT and my mother had numerous DVTs and even PEs. So most of the risk factors show up in me. I had the pain, the swelling, the redness; all of it. You neglected to mention, though, Factor VIII, especially in conjunction with Factor V Leiden. The two together, I was told by a hematologist, combine to make an even stronger clot risk. At least I don't smoke and never have. I AM on clotting medication however and will be for the rest of my life.

over 2 years, said...

TCompression stocking are a must for me but even with every possible device to put them on, apparently having broken L4 and L5, I've recently had another exptremely painful back injury trying to get them on and hae not been able to don them for almost 4 weeks. The best article I've seen on his subject.