Contrary to small animals, now that the human being has stand up on their feet, their brain is located much higher than their heart, but the brain still continuously needs blood.
Under increased vertical acceleration, the blood pressure must be increased to maintain brain irrigation. This has been studied in the past:
The Biology of Human Survival: Life and Death in Extreme Environments, Claude A. Piantadosi:
Human volunteers have tolerated 1.5g for seven days with no apparent
ill effects. However, after just twenty-four hours at 2g, evidence of
significant fluid imbalance is detectable. At 3g to 4g fatigue is
limiting, and above 4g cardiovascular factors limit g tolerance.