A physician will begin the investigation of leg pain with a medical history and a physical examination. The legs will be examined for any signs of swelling, ulcers, abnormal structural conditions or restrictions in range of motion. Sensation will be assessed to determine if there is any numbness and strength tested for weakness. The patient may be asked to use a scale called a pain assessment tool to determine the location and severity of the pain.

The patient may be asked to walk, squat or perform other exercises, if possible, to demonstrate the leg’s function. To determine possible causes of the pain or to rule out other conditions, the following tests may be administered:

• X-rays. Uses low levels of radiation to produce images on a screen or special film. X-rays may be used in diagnosing fractures. Arthritic conditions and joint alignment can also be evaluated.

  

• Doppler ultrasound. Uses a wand to produce images from sound waves that can be viewed on a monitor. Ultrasound can detect blood flow through the leg. It is especially useful in cases of peripheral artery disease (PAD) and deep vein thrombosis (DVT).
  
  
• MRI (magnetic resonance imaging). Uses magnets to produce computerized images on a screen. MRIs can be used to detect growths or tumors in the leg as well as most structural abnormalities.

• CAT scan (computed axial tomography). Use multiple computerized images from many angles to show the leg’s tissues, bones and muscles.
  
  
• Arthrography. Enhances an x-ray of a joint via injection of a contrast medium (dye).
  
  
• Ankle-brachial index. Blood pressure measured at the ankles and arms both at rest and after exercise. A difference in the blood pressure at each location may indicate reduced circulation or PAD.
  
  
• Bone scan. Type of radionuclide imaging used to detect areas of increased or decreased bone uptake of a radioactive material (radionuclides) that is injected into a blood vessel. This material collects in areas of abnormality and can be detected with a special camera. This test may used to detect bone cancer, stress fractures or arthritic conditions.
  
  
• Blood tests. Screen for a wide range of condition that may cause leg pain, ranging from infections to arthritis to sickle cell anemia.
  
  
• Bone density test. Measures the density of bones at certain places such as the hip, spine and ankle. This test can diagnose osteoporosis and monitor bone density over time.
  
  
• Biopsy. A small sample of tissue from the bone or other part of the leg is examined under a microscope. Depending on the part of the leg being tested, it may involve a needle to remove fluid or a larger incision to remove some sort of tissue. Biopsies are usually taken to investigate cancer.