A witness can, at any time, refuse to answer a question by claiming protection under the Fifth Amendment. The person testifying is the defendant in a criminal case: This is an extension of the protection under the Fifth Amendment. Criminal defendants can never be forced to testify. The witness is married to someone involved in the case: Communication between two spouses is considered privileged by courts. This means that in most cases, you can't be forced to testify against your spouse in court.
High blood pressure is simply an increase in blood pressure, while hypertension is a disease. Slight increase in blood pressure is normal in daily life. E.g. when you exercise or walk fast or when you get angry or excited, your heart starts beating fast and this raises your blood pressure.
A blood pressure reading has two numbers: a systolic blood pressure and a diastolic blood pressure. The systolic blood pressure is the maximum pressure the blood exerts on the vessels when the heart is beating. The diastolic blood pressure is the pressure the blood exerts on the vessels in between heartbeats. Hypertension, or high blood pressure, begins when the systolic blood pressure remains above 140 or when the diastolic blood pressure remains above 90.