HypertensionHypertension, which affects more than one billion people, is the major modifiable risk factor for cardiovascular diseaseCardiovascular disease death. Although the pathophysiology of hypertensionHypertension is not entirely understood, disruption of the renin angiotensin systemRenin angiotensin system (RAS), which includes the systemic and brain RAS, has been identified as one of the key causes of numerous forms of hypertensionHypertension. As a result, developing a solid understanding of the fundamental science of RASRenin angiotensin system and the underlying processes of the signalling pathways associated with RASRenin angiotensin system may aid in the development of new therapeutic targets for the treatment of patients with cardiovascular and renal illnesses. Four kinds of angiotensin IIAngiotensin II receptors (AT1RAT4R) have been found, with AT1R playing an essential function in vasoconstriction and receiving the most attention. It has been discovered in numerous areas of the brain, and its distribution is closely related to that of angiotensin-like immunoreactivity in nerve terminals. The impact of AT1R includes the activation of various media and signalling pathways, the most prominent of which are the AT1R/JAK/STAT and Ras/Raf/MAPK pathways. Furthermore, the impact of ATR1 is linked to the regulation of the nuclear factor light-chain enhancer of activated B cells (NFB) and cyclic AMP response element-binding (CREB) pathways. Their action mechanisms are associated with proinflammatory and sympathetic excitatory effects. At1R is involved in nearly every type of hypertensionHypertension, including spontaneous hypertensionHypertension, obesityObesity-induced hypertensionHypertension, renovascular hypertensionHypertension, diabetic hypertensionHypertension, L-NAME-induced hypertensionHypertension, stress-induced hypertensionHypertension, and angiotensin IIAngiotensin II-induced hypertensionHypertension. Acute and chronic central AT1R inhibition are the two forms of central AT1R blockade. The latter is possible by chemical blockage or geneticGenetics modification. This chapter study aimed to emphasize the prevalence, functions, interactions, and modulation methods of central AT1R to treat a variety of clinical disorders. The discovery of angiotensin-derived peptides and the creation of AT2R agonists may give a more comprehensive understanding of RASRenin angiotensin system and innovative treatment methods. © 2025 Elsevier B.V., All rights reserved.