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Updated: Aug 22, 2026

Objectification of Tongue Diagnosis in Traditional Medicine, Data Analysis, and Study Application
Published on: April 14, 2023
[A study on relationship of purple tongue and its regional blood flow]
Cun-Jun Zhang1, Song-Po Wang, Hong Yang
1Department of Traditional Chinese Medicine, First People s Hospital, Shanghai Jiao Tong University, Shanghai 200080, China.
Objective:
To study the relationship of purple tongue and its regional blood flow.
Methods:
Laser-Doppler flow meter was employed to test the volume and velocity of blood flow at different sites of purple tongue (56 cases) and normal tongue (54 cases), and the test results were analyzed.
Results:
The volume of blood flow of purple tongue was significantly lower than that of the normal tongue (P<0.01), while the velocity was significantly higher (P<0.01). The volume and velocity of blood flow at different sites of the tongue were similar without significant difference.
Conclusion:
The volume of blood flow of purple tongue is decreased and the velocity increased. Purple tongue may be caused by dysfunction of the microcirculation of the tongue.
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