Cerebral small vessel disease (SVD) describes a set of pathologies affecting the smallest blood vessels in the brain. SVD contributes to up to a fifth of ischemic and hemorrhagic strokes en is the main vascular cause of dementia. On MRI, SVD is marked by different types of lesions, including white matter abnormalities, and small infarcts and hemorrhages. Recent studies indicate that SVD develops slowly over the years, starting presumably decades before the typical MRI lesions become apparent. High blood pressure plays an important role in the development of SVD MRI lesions. However, it remains unclear exactly how hypertension leads to vascular pathology. To gain more insight into how hypertension leads to SVD it is important to study mechanisms in individuals (largely) free of SVD, that is before midlife. Therefore, the investigators aim to examine abnormalities in brain (micro) structure and vascular function in young patients with hypertension. Furthermore, the investigators aim to determine the effects of blood pressure increase and subsequent blood pressure reduction during a period of withdrawal and restart of blood pressure lowering drugs on brain (micro)structure and vascular function.