# Do DVT clots form in the calf? **URL:** \ **Category:** Factual Questions\ **Created:** [August 13, 2008, 2:31am UTC](https://boards.straightdope.com/t/do-dvt-clots-form-in-the-calf/459807 "2008-08-13T02:31:03Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![SenorBeef](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senorbeef/32/2220_2.png) [@SenorBeef](https://boards.straightdope.com/u/SenorBeef)\ **Post date:** [August 13, 2008, 2:31am UTC](https://boards.straightdope.com/t/do-dvt-clots-form-in-the-calf/459807/1 "2008-08-13T02:31:03Z")
Related to another thread I just made… I’ve been getting abnormal bruising in the middle of my left calf, generally if I walk/stand/etc. for long periods. I went to the hospital when other symptoms made me fear I had a serious blood clot. The doctor ordered an ultrasound to check for DVT in my leg. The ultrasound technician used a compression comparison technique - took an image of an uncompressed part of my leg and then pressed down on it and took another image. She took about 12 sets of images from my groin to my knee, but only one image on my calf, which is where the problem seemed to be. I mentioned this, and she told me that DVT forms in the thigh because there are no deep veins below the knee. That seemed odd to me but I figured she was the expert. So I’m asking - was she right? Given that my syptoms were all below the knee, and she barely spent any time there, did she do the correct procedure? Could I still be in danger from a blood clot? ---
**Author:** ![conurepete](https://avatars.discourse-cdn.com/v4/letter/c/a88e57/32.png) [@conurepete](https://boards.straightdope.com/u/conurepete)\ **Post date:** [August 13, 2008, 3:07am UTC](https://boards.straightdope.com/t/do-dvt-clots-form-in-the-calf/459807/2 "2008-08-13T03:07:19Z")
The 2 clots I found in people were in the calf. One patient presented with swelling and pain and had a classic Homan’s sign. The other patientt had mild swelling, tiny red bruise-dots , complaints of itchy prickles, and something vague that kept making me think things were wrong. I would not have guessed “clot”, but I sent her back to her physician, who did several tests, and the doppler said “clot”. I have also been the cause of at least 4 false alarms were there was no clot ---
**Author:** ![conurepete](https://avatars.discourse-cdn.com/v4/letter/c/a88e57/32.png) [@conurepete](https://boards.straightdope.com/u/conurepete)\ **Post date:** [August 13, 2008, 3:15am UTC](https://boards.straightdope.com/t/do-dvt-clots-form-in-the-calf/459807/3 "2008-08-13T03:15:13Z")
Wait a second- did you go to a Vet? Most of the people I treat are human, it is standard for them to have some big veins deep in the calf: the veins are an important part of the mechanism that moves fluid back from the feet using the pumping motion of the calf muscles during walking. I am not a Doctor. ---
**Author:** ![SenorBeef](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senorbeef/32/2220_2.png) [@SenorBeef](https://boards.straightdope.com/u/SenorBeef)\ **Post date:** [August 13, 2008, 3:25am UTC](https://boards.straightdope.com/t/do-dvt-clots-form-in-the-calf/459807/4 "2008-08-13T03:25:20Z")
No, I went to an ER (at the time I was concerned I had a pulmonary embolism due to other symptoms) and an ultrasound was performed by a technician. ---
**Author:** ![InternetLegend](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/internetlegend/32/13154_2.png) [@InternetLegend](https://boards.straightdope.com/u/InternetLegend)\ **Post date:** [August 13, 2008, 3:32am UTC](https://boards.straightdope.com/t/do-dvt-clots-form-in-the-calf/459807/5 "2008-08-13T03:32:50Z")
My mother’s DVT was diagnosed when an ultrasound done in the ER showed a clot in her calf just below the knee. Her doctor did tell her that she considers it less alarming when a clot is that low, presumably because it’s less likely to travel. However, she still did a year’s worth of Coumadin clinic treatment, and they watch her closely. If I were you, I’d chat about this with my doctor rather than trusting the tech’s medical expertise. ---
**Author:** ![USCDiver](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/uscdiver/32/354_2.png) [@USCDiver](https://boards.straightdope.com/u/USCDiver)\ **Post date:** [August 13, 2008, 4:04am UTC](https://boards.straightdope.com/t/do-dvt-clots-form-in-the-calf/459807/6 "2008-08-13T04:04:46Z")
Technically, the veins below the popliteal are considered ‘superficial veins’ in terms of thombosis. ---
**Author:** ![SenorBeef](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senorbeef/32/2220_2.png) [@SenorBeef](https://boards.straightdope.com/u/SenorBeef)\ **Post date:** [August 13, 2008, 4:08am UTC](https://boards.straightdope.com/t/do-dvt-clots-form-in-the-calf/459807/7 "2008-08-13T04:08:55Z")
Could you elaborate further? Where is the popliteal located? Does being superficial veins in terms of thrombosis mean they don’t represent a threat to dislodge and cause a pulmonary embolism? ---
**Author:** ![mswas](https://avatars.discourse-cdn.com/v4/letter/m/e99b99/32.png) [@mswas](https://boards.straightdope.com/u/mswas)\ **Post date:** [August 13, 2008, 4:28am UTC](https://boards.straightdope.com/t/do-dvt-clots-form-in-the-calf/459807/8 "2008-08-13T04:28:03Z")
[QUOTE=SenorBeef] Could you elaborate further? Where is the popliteal located? Does being superficial veins in terms of thrombosis mean they don’t represent a threat to dislodge and cause a pulmonary embolism? [/QUOTE] The popliteal is behind the knee. > **[Popliteal vein](https://en.wikipedia.org/wiki/Popliteal_vein)** > > The popliteal vein is a vein of the lower limb. It is formed from the anterior tibial vein and the posterior tibial vein. It travels medial to the popliteal artery, and becomes the femoral vein. It drains blood from the leg. It can be assessed using medical ultrasound. It can be affected by popliteal vein entrapment. > The popliteal vein is formed by the junction of the venae comitantes of the anterior tibial vein and the posterior tibial vein at the lower border of the popliteus muscle. It tr... > **[File:Gray582.png](https://en.wikipedia.org/wiki/File:Gray582.png)** > > This work is in the public domain in its country of origin and other countries and areas where the copyright term is the author's life plus 100 years or fewer. > This work is in the public domain in the United States because it was published (or registered with the U.S. Copyright Office) before January 1, 1931. > This tag is designed for use where there may be a need to assert that any enhancements (eg brightness, contrast, colour-matching, sharpening) are in themselves insufficiently creative to g... This picture, about where the number 4 arrow is: [http://msjensen.cehd.umn.edu/WEBANATOMY/cardiovascular/cvs\_veins\_2.jpg](http://msjensen.cehd.umn.edu/WEBANATOMY/cardiovascular/cvs_veins_2.jpg) The distinction here is that in most of the body there are two layers of veins. The ones that serve deeper more near the bone, and the ones that serve more superficial nearer the skin. In the calf it’s not considered ‘Deep’ Venous Thrombosis merely because the layering is different. Popliteal means knee. Your kneecap is called the Popliteus. Below the knee it is the Peroneal vein, and above the knee it’s the femoral vein. It can be a venous thrombosis without being distinguished as Deep Venous Thrombosis because of where it’s located and the lack of a need to distinguish deep from superficial. Now I don’t know how it could relate to the etiology of an embolism specifically, but I think why they are saying it’s less of a concern of dislodging in the leg, is because that’s one of the point of weakest pressure in the body. Veins have much less blood pressure than arteries, particularly that far down in the legs. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [August 13, 2008, 4:57am UTC](https://boards.straightdope.com/t/do-dvt-clots-form-in-the-calf/459807/9 "2008-08-13T04:57:43Z")
In short, I don’t worry much about clots below the level of the knee, because they rarely break off and travel to the lungs, which is what causes all the trouble. IMHO, too much effort is spent on treating clots which are not a significant risk, and not enough on prevention of clots above the knee in susceptible individuals. ---
**Author:** ![KarlGauss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/karlgauss/32/3713_2.png) [@KarlGauss](https://boards.straightdope.com/u/KarlGauss)\ **Post date:** [August 13, 2008, 10:08am UTC](https://boards.straightdope.com/t/do-dvt-clots-form-in-the-calf/459807/10 "2008-08-13T10:08:00Z")
Just to elaborate on what **Qad** said, the dangerous DVTs, and hence the ones looked for, are _above_ the knee. They are the ones that require treatment with blood thinners. Clots can and do form below the knee, but they are clinically of little significance. Still, if a person is at very high risk of a clot above the knee, but the only ones found are below the knee, one option is to repeat the test a week or so later. In that way, one can make sure that the below-knee clot hasn’t extended to a more serious, above-knee type. In other words, to answer your original question, yes, calf clots can evolve into the DVT type (above the knee) but it’s unusual. ---
**Author:** ![BrknButterfly](https://avatars.discourse-cdn.com/v4/letter/b/439d5e/32.png) [@BrknButterfly](https://boards.straightdope.com/u/BrknButterfly)\ **Post date:** [August 13, 2008, 1:59pm UTC](https://boards.straightdope.com/t/do-dvt-clots-form-in-the-calf/459807/11 "2008-08-13T13:59:00Z")
My sister, a few months ago, had leg pain in the back of her calf. She described it much like a charlie horse and pressure that wouldn’t go away. She ignored it and a few days later she felt like she was having, again, what she described as a heart attack. It ultimately got better and she dismissed it. Though her leg was still hurting. After much pressure from her husband and my mother, she made a doctors appointment. She had a blood clot in her calf located in one of the smaller veins. It broke off and traveled through the right side of her heart and formed three blood clots in her lungs. Bottom line. If you don’t trust the results you got, get a second opinion. No one knows your body like you do.