Hypertension
Meaning of Hypertension: Raised pressure rarely announces itself, so it is usually found on a routine check rather than because anything felt wrong.
Definition of Hypertension
Hypertension is persistently raised pressure inside the arteries, recorded as two numbers: the peak as the heart contracts and the resting pressure between beats. It usually causes no symptoms, yet the sustained load stiffens artery walls and thickens the heart muscle. Over years it becomes a leading contributor to stroke, heart failure, kidney disease and damage to the back of the eye.
What do the two numbers mean?
The upper figure, systolic pressure, is the force in the arteries at the moment the left ventricle empties. The lower figure, diastolic pressure, is what remains while the heart refills. Both are reported in millimeters of mercury. Readings move constantly with posture, activity, pain, caffeine and conversation, so a diagnosis rests on repeated measurements taken under controlled conditions, and often on readings taken away from the clinic. Two patterns complicate that: white coat hypertension, where blood pressure is high only in a medical setting, and masked hypertension, where it is normal in clinic and high everywhere else.
What causes it?
| Type | Share of cases | Origin |
|---|---|---|
| Primary, or essential | The large majority | No single cause; genetic tendency plus weight, salt intake, alcohol, inactivity and age |
| Secondary | A minority | An identifiable driver such as kidney disease, narrowed kidney arteries, sleep apnea, thyroid or adrenal disorders, or certain medications |
Secondary causes are looked for particularly when pressure rises abruptly, appears at a young age, or resists several medications, since treating the underlying condition can resolve the problem outright.
What damage does it do?
Constant pressure injures the lining of arteries and accelerates the buildup of plaque, which is the route to heart attack and stroke. The left ventricle thickens to push against the load and eventually stiffens, a path toward congestive heart failure. The kidneys suffer twice over, since their small vessels are damaged by pressure and damaged kidneys in turn raise pressure further. Fine vessels at the back of the eye can be inspected directly, making the retina the one place where the damage is visible without imaging. A separate condition, portal hypertension, describes raised pressure in the vein draining the gut and is unrelated to arterial hypertension.
Also known as
Used in a sentence
Lifestyle changes and medication helped control the patient's hypertension.
Good to know
Diagnosis rests on repeated measurements taken under proper conditions and interpreted against current clinical guidance, not on one isolated reading.
Word origin
Where “Hypertension” comes from
From hyper-, from Greek meaning above or beyond, combined with tension, from Latin tendere, meaning to stretch or strain.