Coagulopathies cause a predisposition to thrombosis and therefore an increased risk of ischaemic stroke. Although the frequency of coagulopathies in patients with stroke is low, the yield for diagnosing coagulopathies is typically greatest in young patients, those with family history of thrombosis, those with repeated unexplained strokes and patients with no vascular risk factors, as Omer H T Ali with Drs Bella Richard and Pradeep Khanna explain.