The cardiovascular system relies on sleep for critical maintenance and regulation. Each night during healthy sleep, blood pressure naturally drops by 10–20% as the body shifts from a stress response to a relaxation state. Sleep also regulates key hormone systems, including the renin-angiotensin-aldosterone system (RAAS), which control blood vessel tone and blood pressure. Without adequate sleep, these vital cardiovascular processes become disrupted, leading to abnormal blood pressure patterns and increased cardiovascular risk.