High blood pressure is the most diagnosed condition in the Unites States today and it is now estimated that it affects about 72 million Americans, including one out of every three adults. But, while we talk about high blood pressure, or hypertension, did you know that there are actually two different types of high blood pressure?

The vast majority of people suffer from what is officially termed essential or primary high blood pressure which frequently has few, if any, symptoms and often develops slowly over a number of years. A smaller, but nonetheless very significant, number of people suffer from secondary high blood pressure which arises out of an underlying medical condition and can sometimes present with a very rapid onset.

The medical conditions which can give rise to secondary high blood pressure are many and varied but here are some of the more common causes:

Obesity. Increasing weight is frequently accompanied by an increase in your heart rate, as your heart is put under pressure to pump an increasing volume of blood around the body, and increased pressure the walls of your arteries.

Sleep Apnea. The frequent interruption to your breathing caused by sleep apnea leads to oxygen deprivation which, in turn, damages the lining of your blood vessels and affects the elasticity needed in these vessels to control blood pressure.

Kidney Problems. The kidneys contain millions of tiny blood vessels and other structures which are designed to filter waste products from the blood. When this filtering process is upset, such as in the case of polycystic kidney disease or hydronephrosis, one of the results is secondary high blood pressure.

Thyroid Problems. Excess or insufficient hormone production within the thyroid gland, seen in conditions such as hypothyroidism and hyperthyroidism, can, either directly or indirectly, result in a rise in blood pressure.

Dietary Supplements. A number of commonly available dietary supplements, such as ginseng and St John's wort, can produce high blood pressure.

This list is not of course exhaustive and could also have included such items as prescription and over-the-counter medication, preeclampsia, Cushing's syndrome, diabetes and more.

High blood pressure, whether primary or secondary, is a serious medical condition which can lead to the development of other life-threatening conditions such as cardiovascular disease, heart disease and kidney failure.