Even after staying awake for over a day, the body's ability to regulate blood pressure through reflexes remains unchanged in healthy men.

Staying awake for up to a day and a half doesn't significantly affect the amount of blood the heart pumps with each beat in healthy men.

After one night without sleep, average blood pressure rises by about 4 points and stays elevated for up to a day and a half in healthy men.

The heart's ability to pump blood per minute per body area remains stable even after 32 hours without sleep in healthy men.

After staying awake for a day, healthy men in their early 30s with average weight experience a small but noticeable rise in blood pressure that stays elevated for up to a day and a half.

After 24 hours without sleep, heart rate drops slightly but then starts rising again over the next 8 hours, suggesting the body's response to sleep loss changes over time.