Essential and secondary hypertension?

The result of hypertension is only one: a blood pressure more than 140/90 mmHg. In most cases (90-95%) of hypertension- so-called essential hypertension- the problem cannot be blamed on any particular cause. On the other hand, there are many causes for secondary hypertension, (more in young people) in which high blood pressure is the result of a specific disorder. In such cases, of course, treatment of the underlying disorder is necessary to bring the blood pressure under control.



JNC-VI Classification of blood pressure for adults age 18 years and older


Systolic mmHg                 Diastolic mmHg


< 120                        and            <80                     


< 130                        and             < 85


130-139                     or               85-89


Stage I*

140-159                     or               90-99

Stage II*

160-179                     or              100-109

Stage III*

180                         or                 110

* Based on the average of two or more readings taken at each of two or more visits after  an initial screening (very important!!!)


In addition to classifying stages of hypertension on the basis of average blood pressure levels, clinicians should specify presence or absence of target organ disease and additional risk factors. This specificity is important for risk classification and treatment.

Furthermore we want to stress that the diagnosis of hypertension should not be made on one visit, unless pressures are above 170/105-110 mmHg: treatment is clearly indicated in these instances. Pressures at levels lower than these should be checked several times over a 3- to 6-month period as lifestyle modifications are made. In my experience, pressures return toward normal levels in approximately 20% to 25% subjects with stage I hypertension.

Suggested initial evaluation for the patient with hypertension

The silent killer

Because high blood pressure seldom has symptoms, many people donít know they have it. This uncontrolled blood pressure can lead to:

q       Stroke. It may result when a blood vessel in the brain is blocked or ruptured. This may damage the brain, and can cause paralysis, loss of speech, or loss of other functions

q       Heart failure. It may develop when the heart can lo longer pump enough blood to meet the bodyís needs. High blood pressure forces the hart to work too hard. Like a stretched out elastic band, the heart muscle eventually weakens and fails.

q       Heart attack. It may occur when one of the coronary arteries that feeds the heart becomes blocked. High blood pressure speeds up the process of arteriosclerosis, in which fatty globs build up on the inside of artery walls.

q       Kidney failure. It may result when tiny blood vessels in the kidneys are damaged. The kidneys can no longer do their job of purifying the blood


However in about 90-95% of cases, the cause of hypertension is unknown many studies have shown several risk factors. They can be differentiate in:

Uncontrollable factors

q       Race. Blacks have high blood pressure more often then whites. It also tends to occur earlier and be more severe in blacks

q       Heredity. A tendency toward hypertension seems to run in families

q       Age. The older a person gets, the more likely he or she is to develop hypertension

q       Sex. Men are more likely to develop hypertension than women, but this varies by age and among ethnic groups


Controllable factors 

q       Obesity. It is an excessive amount of body fat. Obesity and blood pressure are clearly related. Thatís why all obese hypertensive adults should try to get within 15% of their desirable body weight for height and gender

q       Alcohol consumption. Drinking more than one ounce of alcohol a day may increase blood pressure in some people

q       Sodium sensitivity. Reducing sodium (salt) consumption can lower blood pressure in some people

q       Oral contraceptives. Women who take oral contraceptives may develop hypertension

q       Physical inactivity. A sedentary life style contributes to obesity and hypertension

q       Hyperinsulinaemia. More than 50% of people resistant to insulin develop hypertension


Interventions that may reduce the occurrence of hypertension

(more important in subjects with a family history of hypertension)

q       Keep weight as close to optimal as possible

q       Limit sodium intake to less than 2300 mg/day

q       Maintain adequate intake of potassium, calcium, and magnesium. It means a diet high in fruits, vegetables, and low fat diary products

q       Exercise regularly


  Lifestyle modifications suggested by Joint National Committee VI (1997) for hypertension management

(in addition to those listed for prevention)

q       Limit alcohol intake to no more than 30 mL (1 oz) ethanol per day (e.g. 720 mL (24 oz) beer, 300 mL (10 oz) wine, 60 mL (2 oz) 100-proof whiskey or burbon). Approximately Ĺ of these amounts for women and lighter weight people

q       Stop smoking and reduce intake of dietary saturated fat and cholesterol for overall cardiovascular health


Stratification of risk to quantify prognosis

Decisions about the management of patients with hypertension should not be based on the level of blood pressure alone, but also on the presence of other risk factors, concomitant diabetes, target organ damage and cardiovascular and renal disease, as well as other aspects of the patientís personal, medical and social situation.


Other Risk factors

& Discover History

Grade 1

(mild hypertension)

SBP 140 - 159

or DBP 90 - 99

Grade 2

(moderate hypertension)

SBP 160 - 179

or DBP 100 - 109

Grade 3

(severe hypertension)

SBP 180

or DBP 110

I no other risk factors LOW RISK MED RISK HIGH RISK
III 3 or more risk factors or TOD or Diabetes HIGH RISK HIGH RISK VERY HIGH RISK


Factors influencing prognosis

Cardiovascular Risk factors

Target-organ damage (TOD)

Associated clinical conditions (ACC)

Levels of systolic and diastolic BP (grades 1-3)

Left ventricular hypertrophy (electrocardiogram, echocardiogram or radiogram)

Cerebrovascular disease

q       Ischaemic stroke

q       Cerebral haemorrhage

q       Transient ischaemic attack

Men > 55 years

Proteinuria and/or slight elevation of plasma creatinine concentration (1.2-2.0 mg/dl)

Heart disease

q       Myocardial infarction

q       Angina

q       Coronary revascularization

q       Congestive heart failure

Women > 65 years

Ultrasound or radiological evidence of atherosclerotic plaque (carotid, iliac, and femoral arteries, aorta)

Renal disease

q       Diabetic nephropathy

q       Renal failure (plasma creatinine > 2.0 mg/dl


Generalized or focal narrowing of the retinal arteries

Vascular disease

q       Dissecting aneurysm

q       Symptomatic arterial disease

Total cholesterol > 6.5 mmol/l (250 mg/dl)


Advanced hypertensive retinopathy

q       Haemorrhages or exudates

q       papilloedema




Family history of premature cardiovascular disease



Other factors adversely influencing prognosis



Reduced HDL cholesterol



Raised LDL cholesterol



Microalbuminuria in diabetes



Impaired glucose tolerance






Sedentary lifestyle



Raised fibrinogen



High-risk socio-economic group



High-risk ethnic group



High-risk geographic region



TOD corresponds to previous WHO stage 2 hypertension

ACC corresponds to previous WHO stage 3 hypertension


Goal blood pressure

q       < 140/90 mmHg: uncomplicated hypertension, risk group A and B, risk grop C excpt for the following:

q       < 130/85 mmHg: diabetes, renal failure, heart failure

q       < 125/75 mmHg: renal failure with proteinuria > I gram/24 hours


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