High blood pressure is 140/90 or higher. If noted early in pregnancy then it is called chronic hypertension. Medicine should be started to keep the blood pressure below 140/90. You should also start aspirin 81 mg daily to prevent preeclampsia which is a dangerous condition that can affect both the mother and the baby.
The doctor will keep a close eye on you with frequent visits to make sure you blood pressure is normal and the baby is growing. If you develop bad headaches, spots before your eyes, and pain around your liver , that could be very serious and you should see your doctor immediately.
Preeclampsia can only be cured by delivery so it is important to prevent it or delay it as much as possible so the baby isn’t premature. High blood pressure can affect all of the organs in your body including your brain, heart, kidneys, liver, and the uterus where the baby is growing.