High Blood Pressure
DESCRIPTION: Excessive pressure of blood within the arteries that occurs in 20% of adults over 40 years of age.
The heart contracts regularly to pump blood through the arteries under high (systolic) pressure. When the heart relaxes between beats, the blood continues to flow due the lower (diastolic) pressure exerted by the elasticity of the artery walls. Hypertension occurs when one, or both, of these pressures exceed a safe level. Blood pressure readings are written as systolic pressure/diastolic pressure (eg. 120/80) and are measured with a sphygmomanometer. Blood pressure varies with exercise, anxiety, age, fitness, smoking and drinking habits, weight and medications. In an elderly person 160/100 may be acceptable, but in a young woman, 110/60 would be more appropriate. Life insurance companies generally require the blood pressure to be under 136/86 for the person to be acceptable at normal rates. The numbers are a measure of pressure in millimetres of mercury.
The arteries of a person with high blood pressure will become hardened, brittle and may eventually rupture, causing a stroke, heart attack or other serious injury to vital organs.
CAUSE: The majority of patients have `essential’ hypertension, for which there is no single identifiable cause. The identifiable causes include smoking, obesity, kidney disease, oestrogen-containing medications (eg. The contraceptive pill), hyperparathyroidism, phaeochromocytoma (see separate entries) and a number of other rare diseases. High blood pressure may also be a complication of pregnancy, when it can lead to quite serious consequences.
SYMPTOMS: The majority of patients have no symptoms for many years. Those who do have symptoms complain of headaches and tiredness, but only when the blood pressure is very high do the further symptoms of nausea, confusion, and disturbances in vision occur.
INVESTIGATIONS: Once diagnosed, blood and urine tests are performed to see if there is any specific cause. X-rays of the kidneys and an elctrocardiograph (ECG) may also be performed.
TREATMENT: Prevented by keeping weight within reasonable limits, avoid excessive amounts of salt intake, not smoking and regular exercise. There is no cure, but hypertension can be successfully controlled by taking tablets regularly lifelong. A wide range of medications are available, and it takes days or weeks for the tablets to work. Regular checks are essential until the correct is dosage is determined, it is necessary to have blood pressure checked every 3 to 6 months.
COMPLICATIONS: Untreated high blood pressure cause strokes and heart attacks at an earlier age than would be expected with normal blood pressure. Other complications may include kidney damage and bleeding into an eye.
PROGNOSIS: Once controlled, patients should be able to lead a full and active working, sporting and sexual life. However, if untreated, most patients with only moderate hypertension will have critical problem within 20 years.