Brief Answer:
Can be indicative of blockage!
Detailed Answer:
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If a significant difference in temperature is observed at many occassions then it can be due to blockage in any of the branches of left subclavian artery which is a branch of aorta and supplies the left side of body.A angiogram should be performed to rule out blockage due to formation of plaque.In case if artery is blocked then it could be stented.A blockage in left sided artery will disrupt the blood flow to left side of body and as temperature of body is maintained by blood ,there will be significant temperature difference between left and the right side.
However the second simple way is- Stress test should be done and blood pressure should be measured on either side in every stage of exercise.If blood pressure rise is normal then most likely blood supply is normal on either side.
However angiogram is the best method.
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