There's a simple method to check your blood vessels, heart, and blood pressure, says Cao Feng, Deputy Director of Cardiology at Xijing Hospital, Fourth Military Medical University. If your palm quickly regains color within 3-5 seconds after releasing a tight fist, it indicates excellent elasticity in your heart vessels. If your fingertips also turn red and warm up rapidly, it suggests healthy blood pressure.
This occurs because clenching the fist compresses the blood vessels in the palm, interrupting blood flow and causing the skin to turn white (ischemia). When the fist is released, if the paleness in the palm and fingertips quickly fades, it indicates normal heart function and blood pressure.