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.
Blood pressure is constantly monitored by your body and adjusted constantly to meet the needs of your body. This monitoring is performed by baroreceptors. Baroreceptors are special receptors that detect changes in your blood pressure.