In case you are curious about how to check for symptoms of DVT at home, we have a simple quiz based on 10 questions that will help you better understand the diagnosis. If you have Deep Vein Thrombosis, this questionnaire-based symptom checker will guide you on what you should do next.
Please note, this is a tool made to quickly grasp the manifestations. It is important to note that this should not be compared with professional care. It is strongly advised to always seek medical help if you have any kind of illness.
Do I have DVT in my Leg- Quiz
Are you confused between DVT and Varicose Veins?
What is DVT?
DVT is an acronym used for Deep Vein Thrombosis. In medical terms, it is known as Phlebothrombosis.
It is a semi-solid blood clot that usually forms in the deep veins of the leg, however, it can originate from anywhere in the body. It is considered fatal as the blood clot has a high risk of developing pulmonary embolism and sudden death.
Sites
The most common sites for the formation of a thrombus (blood clot) are the Soleal veins which are found in the leg.
The clots in soleal veins later propagate proximally, often becoming detached to cause acute massive pulmonary embolism or moderate-sized emboli can cause pyramidal/wedge-shaped pulmonary infarcts.
The three sites where Deep Vein Thrombosis can originate are:
1. Pelvis
They seem to be reasonably common and involve the internal iliac veins.
Women suffering from PID (pelvic inflammatory disease) are at higher risk of developing DVT.
For men, prostatic veins can be the site of origin. Even though a rectal or vaginal examination may help, it is difficult to identify in clinical practice.
2. Leg
It is very common in the veins of the soleus muscle in the calf. Femoral vein/iliofemoral vein blood clots can occur simultaneously with calf vein thrombosis or individually, causing adductor canal tenderness.
Ilio-femoral vein blood clots are prevalent on the left side because of its long course/ compression by the right iliac artery/often owing to the presence of a web at its entrance into the Inferior Vena Cava.
The prevalence rate of having DVT in both legs is 30%, which should be distinguished from bilateral pedal edema caused by other reasons such as hypoproteinaemia, renal failure, and heart causes.
3. Arm
It can arise naturally, as a result of cervical rib compression, contributing factors of thoracic inlet syndrome, or the arm having been in the hyperabduction state for a lengthy period of time (e.g., painting the ceiling), after axillary lymph node block dissection, after axillary radiotherapy, and periodically as a complication of venepuncture.
Causes
The reason for DVT is hypothesized through the “Virchow’s Triad“. This includes:
- Stasis
- Hypercoagulability
- Vein Wall Injury
The 12 causes of Deep Vein Thrombosis include:
- After Childbirth
- Trauma to the legs, ankles, things, or pelvis
- Excessive use of muscles
- Immobility: Bedridden patients, passengers on long-distance flights or buses (Traveller’s thrombosis).
- Disabling underlying conditions, fatness, lack of mobility, bed rest, pregnancy, 6 weeks after the postpartum period, oral contraceptives (increases the risk by 5 times), and estrogens are all examples of risk factors.
- Postoperative thrombosis (most common cause): This is more common after the age of 40. The incidence rate after major surgery is 30%. Both legs are affected in 30% of cases. Typically seen following prostate surgery, hip surgery, major abdominal surgery, gynecological surgery, and cancer surgery. Bed rest for more than three days after surgery raises the risk of DVT.
- In visceral cancers such as cancer of the pancreas or stomach, spontaneous blood clot formation is common. It is frequently the migrating type.
- Thrombus can begin in a venous tributary and spread into the main vein.
- Thrombocytosis, polycythemia vera.
- Thrombophilia and Deficiencies of antithrombin 111, protein C, protein S, and factor V of Leiden.
- Recent heart attacks, heart failure, and nephrotic syndrome are all possibilities.
- Thrombosis can occur in those who sit glued to computers for a long time (‘ethrombosis’).
- Smoking
Here is a video on how these blood clots form:
Signs and Symptoms
In a nutshell, the following are the features of DVT:
- 60% of the time it is silent.
- The first symptom is fever.
- Calf swelling which is tight, tender, warm, pale/bluish, and shining.
- Positive Signs- Homan’s, Mose’s, or Neuhof’s signs
- Positive Inverted Champagne Bottle Sign
- Components of pulmonary embolism
Important: Calf swelling + Positive Homan's sign (pain on dorsiflexion) > THINK OF DVT EVEN IN ABSENCE OF RISK FACTORS OR SKIN CHANGES
Earliest Signs
- Fever is the first symptom.
- Pain along with swelling in the calf and thighs is frequent. The pain is frequently so acute that the patient is unable to flex (or move) the leg.
- The skin on the leg is stretched and shiny, and it is tense, painful, hot, pale, or bluish.
- Positive Homan’s sign: Calf discomfort caused by passive forceful dorsiflexion of the foot with an extended knee.
- Mose’s sign: Squeezing the lower section of the leg from side to side produces pain. Gentleness is essential, or else it may detach a clot and trigger an embolus to develop.
- Neuhof’s sign is characterized by thickness and profound soreness felt while assessing a patient deep in the calf muscles.
- Often these DVTs are undetected and show abruptly with pulmonary embolism symptoms such as chest discomfort, shortness of breath, and hemoptysis.
How to Check for DVT at Home?
Deep Vein Thrombosis is a lethal diagnosis and being careless with it can be deadly. There are plenty of guides around the internet that explain the steps of performing various tests at home to check for a blood clot in your leg.
We strictly advise you not to perform such tests and these should be exclusively performed by trained physicians.
Incorrectly performing the procedure can lead to the detachment of the clot and cause it to travel to vital organs where it can cause Pulmonary Embolism in the Lungs, Stroke in the brain, Atrial fibrillation or cardiac arrest in the heart, and ultimately, death.
If you think you have DVT, we recommend you visit A&E and get yourself checked promptly so that emergency drugs are started immediately. Any delay in the diagnosis can be life-threatening.
Diagnosis
The diagnosis involves three components which are:
1. Physical Examination
This includes checking for signs and symptoms of Deep Vein Thrombosis which are discussed above. Additionally, checking the pulse is a crucial part of the examination.
2. Imaging Studies
USG Doppler (Ultrasound Venous Doppler with Duplex Scanning)
This can detect the presence of blood clots in the deep veins. It will exhibit a non-compressible vein that is wider than normal.
Venogram
After establishing a tourniquet to the superficial system, contrast material is injected into the venous system to provide a clear image of the veins. This distinguishes between occlusive and non-occlusive blood clots. However, given that it is invasive, it is not routinely used.
Other Imaging Tests
Blood Tests
- D-Dimer- The most useful and frequently performed blood test.
- Other relevant test includes the study of fibrin degradation products (FOP).
- The D-dimer test measures cross-linked degradation products and interpret plasmin activity on fibrin.
- A negative D-dimer test is more useful.
- Other blood tests like CBC (Complete Blood Count), PT (Prothrombin time), and Activated Partial Thromboplastin Time (aPTT) are frequently performed in addition to D-Dimer.
Well’s Score Mnemonic for DVT
Following is an acronym for Well’s Score which is used to predict the risk for Deep Venous Thrombosis:
- BEST CAP (1 score for each) (-2 for Alternative Diagnosis Likely)
- Bedridden >3 days/ Past surgery within 12 weeks
- Entire leg swollen
- Swelling- Entire leg or Calf Swelling >3cm
- Tenderness
- Collateral Superficial Veins
- Active Cancer
- Paralysis, Paresis or Plaster, Previous DVT< Pitting Oedema
Clinical Features | Points |
---|---|
Active cancer (on treatment, treated in the last 6 months or palliative) | 1 |
Paralysis, Paresis, or Plaster Immobilisation of the lower limb | 1 |
Bedridden for 3 days or more, or major surgery in the past 12 weeks requiring general or regional anesthesia | 1 |
Localized tenderness along the distribution of the deep venous system | 1 |
Entire leg swollen | 1 |
Calf Swelling 3cm larger than the symptomatic leg | 1 |
Collateral superficial veins (non-varicose) | 1 |
Pitting edema in the affected leg only | 1 |
Previous DVT | 1 |
Alternate Diagnosis is at least as likely as DVT | -2 |
It is important to note that the Do I have DVT in my Leg Quiz above does not take into account one of the factors from this table- “Alternate Diagnosis is at least as likely as DVT”.
Differential Diagnosis
There are 6 possible differential diagnoses that can be closely related to Deep Vein Thrombosis:
- Baker’s cyst rupture
- Plantaris tendon rupture
- Haematoma in the calf muscle
- Superficial thrombophlebitis
- Cellulitis
- Arterial Occlusion
Additional Notes on Differential Diagnosis of DVT
- Arterial Occlusion
- 6P features of Acute Limb Ischemia
- Pain (Sudden)
- Pallor
- Paralysis
- Paraesthesia (Numbness)
- Perishing cold
- 6P features of Acute Limb Ischemia
- Superficial Thrombophlebitis
- Sore Legs (Painful legs)
- Swollen Varicose Veins
- No calf tenderness
- High D-Dimer
- Treatment- NSAIDs
Treatment
Initial Care
- Rest, limb elevation, and crepe bandaging of the entire limb.
- Anticoagulants (blood thinners) are started as soon as possible to minimize the risk of a pulmonary embolism.
Fixed Blood Clot
In cases where the thrombus is fixed, anticoagulants (blood thinners) are administered through IV access.
Updates on the Management of DVT with Anticoagulants
According to the 2020 NICE CKS Guidelines in the UK, the following is a summary of updates that were made:
- First line- DOACs– Apixaban or Rivaroxaban as first-line Management for Deep Vein Thrombosis (2020 NICE Guidelines for the UK)
- Not Suitable- Then LMWH followed by
- Dabigatran or Edoxaban
- Vitamin K Antagonist (VKA, i.e. Warfarin)
- Not Suitable- Then LMWH followed by
- Cancer- DOAC unless contraindicated
- If Severe Renal Impairment (eg. GFR<15/min)- LMWH, Unfractionated Heparin or LMWH followed by Warfarin
- If Anticoagulation is CONTRAINDICATED (eg. recent hemorrhagic stroke)- Surgical Thrombectomy (Percutaneous Mechanical Thrombectomy)
- Length of Anti-coagulation
- At least 3 months (3-6 months)
- DVT in Pregnancy
- Antiphospholipid Syndrome (specifically “triple positive” in guidance)- Aspirin + LMWH
- Both DOACs and Warfarin are contraindicated during pregnancy
- Any pregnant woman presents with suggestive features of Deep Vein Thrombosis
- start LMWH until the diagnosis is ruled out
Here,
- DOAC- Direct Oral Anticoagulants
- Dabigatran
- Apixaban
- Rivaroxaban
- Edoxaban
- LMWH- Low Molecular Weight Heparin
- GFR- Glomerular Filtration Rate
Free Floating Blood Clot
A free thrombus is dangerous as it can travel anywhere in the body and cause fatality. If it reaches the lung, this will result in Pulmonary Embolism. Therefore, it is necessary to treat them urgently. It is usually done by:
- Fibrinolysis
- Thrombectomy using Fogarty’s catheter
- IVC filter
Prevention
- Care must be made to ensure good leg posture with no pressure on the calf muscles.
- During significant surgeries, such as laparoscopic surgeries, a pressure bandage must be put on the legs. Elevation, massage, elastic compression bandage, early mobilization, and sustaining hydration are all important postoperative strategies.
- To prevent inefficient blood circulation, several techniques such as progressive static compression, elastic stockings, electrical stimulation of leg muscles, and pneumatic compression can be used.
- Dextran 70, 500 mL intravenously during surgery and another 500 mL 24 hours later, can also be administered to combat DVT.
- Smoking increases blood viscosity and should be discouraged.
- Patients taking contraceptive pills or estrogens should halt the medication 6-8 weeks before any elective procedures.
- Blood thinners (Anticoagulants- DOAC) should be started prophylactically to reduce the risk of pulmonary embolism.
Sequale
- Pulmonary embolism- 15%
- Venous gangrene; infection
- Chronic venous hypertension around the ankle producing venous ulcers-chronic venous insufficiency, partial recanalization
- DVT recurrence- 30%
- Proximal thrombus propagation- 20-30%
FAQs
When to choose between D-Dimer or USG for DVT?
This can be answered based on Well’s Score. If the well’s score is 2 or more, then perform USG of Legs instead of D-Dimer. Similarly, if the score is less than 2, D-Dimer is sufficient.
What if already on the maximum dose of Rivaroxaban?
If a patient is already on DOAC (Direct Oral Anti-coagulants) and presents with calf pain, edema, and swelling, then request D-Dimer and arrange USG legs within 24 hours (Preferred within 4 hours). A combination of Warfarin and LMWH is started additionally.
When to say DVT is Likely or Unlikely?
If the Well’s Score >_2 = DVT Likely. Otherwise, Well’s Score <2 = DVT Unlikely.
How can you have DVT without knowing?
It is mostly the case because 60% of the cases are silent and do not have any presentation or symptoms. Therefore, it is crucial to not miss any critical signs such as tenderness in the calf, swelling of the entire leg, previously documented DVT, and any discoloration of the leg.
Additional Resources
- Well’s vs Modified Well’s Criteria
- Learning Deep Venous Thrombosis through NHS
- DVT vs Varicose Veins