High Blood Pressure Causes
Can Be Exposed...
If you know where to look. And you must look because high blood pressure causes when found are often curable or manageable. Remembering the law that Pressure equals Flow times Resistance helps to understand the following:
Ways To Raise Blood Pressure
- Increase the beating frequency of the heart, the "heart rate". This increases the amount of blood flowing through the blood vessels.
- Increase the force of contraction of the heart. This, too, increases the amount of blood flowing through the blood vessels.
- Constrict the small arteries. This raises resistance to flow and therefore pressure rises.
- Constrict the small veins. Similar effect to arterial constriction.
- Increase the amount of blood in the vascular compartment. This raises flow which raises pressure.
Disease States That Are High Blood Pressure Causes
- Obstructive sleep apnea results in a state of reduced oxygenation (hypoxia) which in turn induces the release of epinephrine (adrenaline) creating an adrenergic state, stimulating the heart as in 1 and 2 above.
- Aldosteronism: Excess aldosterone causes sodium and water retention and the loss of potassium in the urine. High serum sodium and low serum potassium suggest this disorder. Number 5 above.
- Renovascular hypertension: Obstruction of the renal (kidney) arteries results in insufficient blood supply which damages the kidney. This in turn raises the blood pressure. It is estimated that between 1% and 5% of all cases of hypertension fall into this category. This should be found because it is usually curable.
- Primary renal disease is one of the high blood pressure causes and may very well be one of the consequences. Sometimes it is impossible to tell which came first. Its mechanism is to retain sodium and water. It can be identified though and this is important to be able to slow the process. Early identification becomes especially important in early hypertension before significant kidney damage occurs, thus preventing it. Way number 5 above.
- Catecholamines: A group of compounds including epinephrine, norepinephrine and dopamine having a sympathetic nervous system action. Stress induces their release and thus has implications as widespread as is stress. Pheochromocytoma raises blood pressure by this mechanism and probably so does sleep apnea. Some substances and medications have catecholamine actions notably cocaine, decongestants, stimulants, weight-loss preparations and ephedra or Ma Huang. (Ephedra is now banned.)
- Cushing’s Syndrome: An excess of glucocorticoid (steroid) hormones secreted by the adrenal glands and acts similarly to Ways 2 and 4 above to raise blood pressure. Many other bad effects on most bodily systems. A bad one but fortunately not common.
- Coarctation of the aorta: Congenital obstruction of the aorta between the left arm artery and the kidney arteries resulting in high pressure above the obstruction and under perfusion of the kidney below it. This in turn releases renin, an enzyme that helps to generate vasoconstrictors which raise BP. These are usually found in childhood and rightly so because of the association with premature death. Another one of the high blood pressure causes that is surgically curable. Way number 3 above.
- Endocrine (hormone) disorders:
Hyperthyroidism and Hypothyroidism are both causes of high blood pressure. The first affects the systolic primarily and the second affects the diastolic primarily.
Hyperparathyroidism has an incidence of 1% in hypertensives and is potentially curable. How it raises BP is unclear.
Pheochromocytoma is rare but has a lot of interest and is getting its own page soon. Acromegaly is also rare.
- Emotional factors: Interesting results from a 15-year observational study:
Psychological traits associated with increased risk of hypertension are time urgency/impatience and hostility.
Traits not associated are depression, anxiety (boy that’s a relief), and achievement striving/competitiveness.
Drugs and Substances Can Be High Blood Pressure Causes
- Nonsteroidal anti-inflammatory drugs or NSAIDs have an anti-prostaglandin effect on the kidney thus raising blood pressure. More effect on hypertensive patients and even more effect on those taking beta-blockers and/or diuretics. Aspirin or sulindac reduces the effect.
- Illicit drugs: Cocaine and amphetamine and their ilk are obvious and hardly need discussion. Also belong in the next category.
- Sympathomimetics: Decongestants and weight loss pills. Watch these.
- Oral contraceptives have only a mild effect in the amounts used most often. Worse in smokers over age 35. Is there anything smoking doesn’t make worse?
- Immunosuppressive agents raise blood pressure in 65% to 100% of solid-organ transplant patients.
- Alcohol, nicotine and caffeine:Alcohol to excess really does it. Nicotine probably is not a cause of sustained elevation but who needs another reason to quit. Caffeine probably doesn’t cause chronic hypertension.
An odd duck that should be mentioned is licorice.
- Miscellaneous other drugs, mostly prescription, can elevate but leave these to your doctor. On the other hand you should always ask.
Doctor’s Practical Guide
If you have not already read the sister page on classes of hypertension and theories of how pressure is raised
go here: Causes of High Blood Pressure
If, as noted above, 1% to 5% of all cases of hypertension are renovascular in origin then screening should be done routinely in my estimation. I do not know why it is not. Listening for abnormal sounds (bruit) from the obstruction picks up only 50% of cases.
Of the drugs listed above that can be high blood pressure causes the ones most likely to be encountered but most likely to be discounted are the NSAIDs, nicotine, alcohol, decongestants, weight loss pills, and licorice. I think almost everyone knows about estrogen, cocaine and amphetamine. Which brings us to:
Dr. Moloney’s Law (that’s me): If a patient has something wrong and the cause is not obvious then suspect any and all substances and medications, prescription and non-prescription, that he/she might be taking.
It is amazing how often a problem can be solved by medication and substance adjustments.
When it comes to high blood pressure causes be quick to suspect drugs and substances.
Lastly, the only way to know if one of these high blood pressure causes is raising your pressure is to monitor it yourself. See this page on how and why take your own pressure:
How To Take Blood Pressure
The four pages regarding causes of high blood pressure are:
High Blood Pressure Causes
Causes of High Blood Pressure
What Causes High Blood Pressure
Cause of High Blood Pressure
Follow High Blood Pressure Causes with the Homepage