Hypertension is the medical term for high blood pressure. It does not
refer to being tense, nervous or hyperactive. You can be a calm, relaxed
person and still have high blood pressure.
High blood pressure usually has no symptoms. In fact, many people
have high blood pressure for years without knowing it. That is why it’s
so dangerous.
The only way to find out if you have high blood pressure is to have your
blood pressure checked. You should check your blood pressure at least
once every two years.
A single elevated blood pressure reading does not mean you have high
blood pressure, but it’s a sign that further observation is required.
Certain diseases, such as kidney disease, can cause high blood
pressure. In 90 to 95 percent of cases, the cause of high blood pressure
is unknown.
Optimal blood pressure with respect to cardiovascular risk is less than
120/80 mm Hg. However, unusually low readings should be evaluated for
clinical significant
This term related to an elevation of either the systolic or diastolic blood
pressure or both.
Types of Hypertension:
There are two main types of hypertension:
I-Essential hypertension:
this is the major type of hypertension in which there is no identifiable
cause for the disorder called (primary Hypertension) also the cause of
hypertension is unknown, it contribute for more than 90% of the
hypertensive patients.
II-non Essential hypertension:
In this type patients only account for 10% of the hypertensive
population, this type with known causes, and these causes are:
-Primary hyperaldosteronism (conns disease)
-Contraction of the aorta
-Cushings syndrome
-Pheochromocytoma (Adrenal tumor)
-Pregnancy
-Drug induced:
(Corticoids, alcohol, anorectics, decongestants, cyclosporin, Estrogens,
licorice, MAO, NSAID, Oral contraceptives)
-Increased intracraneal pressure,
Pheochromocytoma:
It is a tumor of adrenomedullary tissue that secrete norepinephrin and a
variable amount of epinephrine. It is a rare tumor, its detection is very
important for hypertension diagnosis and treatment.
This type of tumor can be detected by measuring the amount of
epinephrine in the blood, which is increased in case of tumor.
Methyldopa, tetracycline and quinidine may increase epinephrine
concentration in the blood and give false results.
Signs and symptoms can be related to a very high plasma concentration
of catecholamines including hypertension characterized by headache,
flushing and hyperglycemia.
Cushing syndrome:
Caused by an excess of circulating cortisol due to hyperstimulation of
ACTH.
Features of it: *obesity (moon face) *hyperglycemia because cortisol
opposes insulin function *increase protein catabolism *hypertension
caused by an increased in sodium and water retention due to the
mineralocorticoid effect of cortisol.
Conns disease:
It is a primary hyper aldosteronism, and the increase in aldosteron
release causes an increase in sodium retention and cause to increase
blood pressure.
III-Office Hypertension:
Blood pressure elevated in case of clinic visit, in which blood pressure in
this case is higher than normal ,and when checked out of the clinic with
out seeing the doctor blood pressure will be normal.
IV-Isolated systolic Hypertension:
Itis an elevated systolic blood pressure with normal diastolic pressure,in
this case systolic blood pressure is more or equal to 160mmHg with
diastolic pressure between 90-95mmHg ,according to Framingham ISH
related to age above 55Years.
Pathophysiology:
Number of factors may affect arterial blood pressure. Blood pressure
normally regulated by compensatory mechanisms that respond to
changes to cardiac demand. An increase in cardiac out put (CO) normally
result in compensatory decease in total peripheral resistance (TPR); and
also an increase in TPR decrease in CO, these occur in order to maintain
a main arterial pressure (MAP),this as follows
MAP = CO + TPR
Cardiovascular Diseases
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Hypertension
