High blood pressure is said to be present if it is persistently at or above 140/90 mmHg in adults. The higher number corresponds to systolic pressure while lower numbers correspond to diastolic pressure.
Decisions about aggressiveness of treatment are made according to the classification:
Normal: systolic < 120 mmHg, diastolic < 80 mmHg
Prehypertension: systolic < 120-139 mmHg, diastolic < 80-89 mmHg
Stage 1: systolic < 140-159 mmHg, diastolic < 90-99 mmHg
Stage 2: systolic < 160-179 mmHg, diastolic < 100-109 mmHg
Stage 3 (hypertensive crisis): systolic > 180 mmHg, diastolic > 110 mmHg
Prehypertension is not considered abnormal, however, advise your patient for lifestyle modifications.
Primary (essential) and secondary hypertension:
1. Systolic Blood Pressure (SBP)
SBP correlates with stroke volume and the compliance of the aorta.
DBP correlates with the volume of blood in the aorta during diastole. Diastolic blood pressure will rise with an increase in peripheral vascular resistance, blood viscosity, and heart rate.
Primary hypertension: the most common cause of hypertension is essential hypertension (95% cases of hypertension).
Secondary Hypertension: occurs due to preexisting pathology:
1)Renal disease (3-5% cases)
Doppler ultrasound can be used for diagnosing renal artery stenosis. Most accurate is angiogram. Treatment is renal artery angioplasty and stenting.
It is treated with a combination of low sodium diet and potassium-sparing diuretic drugs.
2) Endocrine conditions (1-2% cases)
3) Vascular conditions
4) Epigenetic phenomena: DNA methylation and histone modification.
5) Oral contraceptives: activates renin-angiotensinogen system because hepatic synthesis of angiotensinogen is induced by the estrogen component of oral contraceptives. The best way to manage this cause of hypertension is to stop oral contraceptives and hypertension goes away in 6 months.
6) Exogenous steroids: increases blood pressure by volume expansion.
7) NSAIDs: blocks both cyclooxygenase-1 (COX-1) and COX-2 enzymes. COX-2 has a natriuretic effect. The inhibition of COX-2 can inhibit its natriuretic effect. NSAIDs also inhibit the vasodilation effects of prostaglandins at renal afferents and produces vasoconstriction factor (endothelin-1).
8) Neurogenic causes: brain tumor, bulbar poliomyelitis, intracranial hypertension
9) Drugs and toxins: alcohol, cocaine, cyclosporine, tacrolimus, NSAIDs, erythropoietin, adrenergic medications, decongestants containing ephedrine, herbal remedies containing licorice or ephedrine.
10) Smoking: causes vasoconstriction and damages arteries leading to atherosclerosis, thromboangitis obliterans, Raynaud’s phenomenon.
11) Pregnancy: gestational hypertension (new onset hypertension that develops after 20th week of pregnancy), pre-eclampsia (hypertension + proteinuria) or eclampsia (hypertension + seizures)
Hypertension is usually an asymptomatic condition.
In other words, headache is not a reliable symptom of hypertension. Other findings that might be present in chronic hypertension are:
Diabetics: ACE inhibitors are the first line of drug
Benign prostatic hyperplasia: alpha-blockers
Migraine headache: beta blockers, calcium channel blockers
Pregnancy: labetalol, methyldopa, hydralazine (for acute reduction)
Next: Hypertension in Pregnancy, Hypertensive Crisis