If the headache patient has 4-5 features (see right), the chance he/she has migraine is 92%. But if he/she has only 0-2 features, then his/her chance is only 17%.(Assuming migraine prevalence is 33%)

Pulsatile quality of headache Headache duration of 4-72 hours Unilateral headache Nausea or vomiting Disabling intensity of headache