Causes of High Blood Pressure

...Are present only in 5 to 10% of cases. Causes of high blood pressure for the rest are theories. Learn what these are and how we approach this problem (we use a wide net).

Classes of High Blood Pressure

You would realize from reading the Homepage that we divide high blood pressure into two major classes:

  •   Essential Hypertension: Represents that 90% of cases where no cause is identifiable. There is a cause, we just haven’t found it yet. We have some nice theories on the causes of high blood pressure.

  •   Secondary Hypertension: Represents that 5 to 10% of cases that have an identifiable cause. Here is where the causes of high blood pressure are identified.

You would realize from reading the Normal Blood Pressure page and the Lower Blood Pressure page that there are foods, substances, lifestyle factors, psychological factors and bodily states that act to raise blood pressure and lower it as well. These affect both Essential Hypertension and Secondary Hypertension. They are very fertile grounds for lowering blood pressure, possibly eliminating it, softening its impact or reducing its needed treatment.

Theories of the Causes of High Blood Pressure

We deal with theories only with Essential Hypertension because in Secondary Hypertension the cause is known.

Essential hypertension, 90% of cases, is of unknown cause and due to the diversity of the possible derangements there is little likelihood of a single cause being found. Heredity is a predisposing factor but by unclear mechanism. Environmental factors such as salt, obesity and stress act only in those predisposed by heredity. The causative mechanisms must act eventually to either raise peripheral resistance or increase cardiac output or both. Just consider the law that BP is equal to blood flow times resistance, thus raising either flow or resistance raises BP.

The actual theories:

  • Stimulation of the sympathetic nervous system raises BP but whether it is in the nervous system itself, or the heart muscle or the vascular smooth muscle that it stimulates is unknown. A high resting pulse rate, a result of sympathetic stimulation, is a well-known predictor of future hypertension.

  • Sodium accumulation in the cell wall making the cell more responsive to sympathetic stimulation, constricting blood vessels and increasing resistance.

  • Derangement of the renin-angiotensin-aldosterone system releases potent vasoconstrictors. Increased resistance to flow results which therefore increased BP.

  • The mosaic theory suggests that after a single factor acts to raise BP then multiple factors sustain the elevation.

  • Deficiency of a vasodilator substance such as bradykinin could cause vasoconstriction and resultant increased BP.

Again these are theories that represent some of the thinking of medical scientists and should be viewed as such. Perhaps the number of theories is inversely proportional to the amount of real evidence.

Actual Causes of High Blood Pressure

Secondary hypertension consists of those cases (up to 10%) that have an identifiable cause. No need to speculate here. This is a large subject and deserves a separate write-up at this sister page: High Blood Pressure Causes There are listed the most common causes of high blood pressure (secondary hypertension) with discussion of other characteristics.

Doctor's Practical Guide

If you have elevated readings make sure they are not among the 25% that are false elevations by reading it yourself. See How To Take Blood Pressure If you verify that you truly do have elevated readings then see your doctor. We have a very good protocol worked out regarding what to do with a newly discovered case of hypertension. This is to find that 5% to 10% of people who have secondary hypertension which is potentially curable.

The new patient with hypertension is given the following list of tests: Medical History, Physical Examination, CBC, Urinalysis, Potassium, Sodium, Creatinine, Glucose, Cholesterol Profile and EKG.

If the history, physical exam and routine tests as above reveal some abnormal findings such as abnormal potassium or sleep apnea or kidney disease, etc, then other tests are indicated. Some of these are sleep studies, kidney excretion tests, special CAT scans, special MRIs, ultrasound and other serum tests including thyroid and parathyroid levels.

As always, partner with your doctor to get the best result for you.

Next read High Blood Pressure Causes for the rundown on disease states that cause Secondary Hypertension.

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 Causes of High Blood Pressure with the Homepage