Blood Pressure is a measurement of the force exerted on the blood vessels of the heart as the blood moves along. If a client suffers from hypertension i.e. high blood pressure, or low blood pressure i.e. hypotension, the therapist needs to know this and will decide how to adapt the treatment accordingly. The client may need permission in writing from their doctor in order for the massage to take place or the client may be asked to sign a disclaimer. If the client has very high blood pressure they will be contraindicated from having massage. See List of Contraindications.