Check your blood pressure
Galaxy phones have had a heart rate monitor since the Galaxy S5. S9 adds a blood pressure reading. They call it "cardiac load factor". This is a health function to give a picture of your blood pressure, but Samsung does not make any medical claims. You still need to contact your doctor for medical advice or to monitor a condition.
In addition, Samsung has partnered with UCSF to share your blood pressure information and can monitor your stress levels to guide you to lower your blood pressure.
Go to Samsung app folder> Samsung Health> print HLF .