VWF and Headache: However, when comparing the HFEM (8–14 migraine days/month) and CM group (≥ 15 headache days/month, of which ≥ 8 days are days with a migraine), in other terms, the subgroup of patients with ≥ 8 days of headache per month versus controls, statistically significant differences also appear in hsCRP 2.68 versus 1.64 mg/dL; p = 0.049, vWF antigen (133% vs. 110%; p = 0.020, and vWF activity (111% vs. 90%; p = 0.010) which were significantly greater in the patients than in the controls.