Stress has a well-known association with high blood pressure (hypertension), but a direct causal relationship between stress and high blood pressure has not been established yet. Both mental stress and physiological stress can result in raised blood pressure, although exact mechanisms may differ slightly in these two cases. A well-known example of mental stress causing raised blood pressure is ‘white coat hypertension’. It refers to raised blood pressure readings obtained when blood pressure is measured in a clinic, but normal blood pressure readings in home and other places. White coat hypertension occurs due to mental stress or anxiety some people experience when visiting a hospital or clinic. Physical stresses like strenuous work, long duty hours, inadequate sleep etc. are included into physiological stress.
Acute stress has been clearly demonstrated to result in a temporary increase in the blood pressure, but role of long term stress in causing hypertension is still a topic of debate. Stress raises blood levels of many chemicals that cause an increase in blood pressure. The most important ones are catecholamine (e.g. Epinephrine), cortisol, endorphins, aldosterone and vasopressin. Long standing stress results in raised baseline levels of such hormones, and thus resulting in increased blood pressure. Stress induced increase in blood pressure may also be partly due to activation of sympathetic nervous system.
Although current evidence indicates that stress by itself does not cause hypertension, stress in combination with other risk factors might cause hypertension or worsen an already existing one. Also, stress can induce behaviors like overeating, poor sleep, cigarette smoking, alcohol consumption, etc. that are known risk factors for hypertension. Thus, most probably stress has an indirect effect on raising the blood pressure.
Quantifying stress is a difficult task, and it is one of the major hurdles in establishing a causal relation between stress and high blood pressure and measuring the effectiveness of relaxation therapies on blood pressure control. Same amount of office workload may be perceived as a different amount of stress by different people.
Addressing stress and adopting lifestyle changes to reduce it or better cope with it are an important part of the non-pharmacological management of essential hypertension. Since often it is impossible to pin point stress as the cause of hypertension, so any primary hypertension with no known cause is managed on similar lines using both medications and lifestyle modifications. Various non-pharmacological treatments to counter stress like relaxation therapies (meditation, yoga, massage, tia chi etc.), acupressure, biofeedback, music therapy etc. are becoming increasingly popular. Research is going on to evaluate their effectiveness in decreasing the blood pressure. However, since they have minimal side effects and improve overall health of a person, they are worth trying even though their effectiveness in reducing the blood pressure significantly has not yet been proven consistently.