It is a clinical diagnostic method to determine a patient's haemorrhagic tendency.

It assesses fragility of capillary walls and is used to identify thrombocytopenia (a reduced platelet count) and is associated with low vitamin C or scurvy.

The test is positive if there are more than 10 to 20 petechiae per square inch.

[1][2] The test was once part of the World Health Organization (WHO) algorithm for diagnosis of dengue fever,[3] however it is no longer used in the latest WHO guidance.

[4] Studies have shown that the tourniquet test has low predictive value for dengue fever and should be used in conjunction with other tests for a reliable diagnosis.