About this procedure
Ultrasound of the limb veins helps assess vein patency, detect blood clots and examine venous blood flow. Doppler imaging provides information about flow direction; when scanning leg veins, the clinician may also assess valve function.
During the scan, the clinician moves a transducer along the veins, may apply gentle pressure to test whether they compress normally and checks blood flow. Your position may change, for example when assessing venous reflux.
Special preparation is usually unnecessary. Wear clothing that allows access to the area being scanned. Tell the clinician about previous clots, anticoagulant treatment and earlier vein surgery. Do not stop any prescribed medicine yourself.
Ultrasound does not show every deep vein in the abdomen or pelvis equally well; smaller or deeper segments may be difficult to visualize. When a clot is suspected, the doctor decides whether additional investigations are needed.
The findings are documented in a medical report describing visible structures and limitations of the method. Follow-up is guided by a clinician when symptoms or abnormalities are present. A single ultrasound finding is not always a final diagnosis and should not be used to start treatment without advice. Earlier reports help when comparing repeated scans, although measurement differences may reflect technique or scanning conditions.
Signs and symptoms
- Swelling of one limb, heaviness, pain or localized tenderness when a clinician recommends assessment.
- Varicose veins and treatment planning with a vein specialist.
- Follow-up after venous thrombosis according to an agreed care plan.
Diagnosis and tests
A transducer is moved along the veins and gentle compression may be used to assess patency. The patient's position may be adjusted to examine venous reflux.
Not all deep veins of the pelvis or abdomen can be assessed by this technique. The physician determines whether further testing is needed when thrombosis is suspected.
Care and treatment approaches
Ultrasound is a diagnostic test, not a treatment. Consultations, laboratory tests or repeat imaging are determined by the clinical situation. Do not prescribe medicines or procedures for yourself on the basis of a scan report.
When to seek urgent care
Sudden marked swelling or pain in a leg requires prompt medical assessment. Call 103 immediately if breathlessness, chest pain or fainting occurs at the same time.
Frequently asked questions
Can an ultrasound detect a blood clot?
Venous ultrasound is commonly used to look for clots, but its accuracy varies with the area and the clinical circumstances.
Do I need any preparation?
Usually no special preparation is required for scanning limb veins, except allowing access to the area.
Should both legs be scanned?
The clinician determines the extent based on symptoms, examination and referral; the price list may offer different options.
Important information
A medical consultation is needed for diagnosis and treatment recommendations.
Self-treatment can be harmful to your health.
