What Are the Causes of Uncontrolled Hypertension?

Uncontrolled hypertension is defined by the American Heart Association (AHA) as blood pressure greater than 140/90 mm Hg (millimeters of mercury). Nationwide, there may be more than 40 million Americans with uncontrolled hypertension, according to a 2005 study in the AHA journal "Circulation."

Initial Causes of Hypertension

• Blood pressure tends to rise with age, according to the National Heart, Lung and Blood Institute, so it must be monitored and treated if it creeps into the danger zone above 140/90. Other causes of high blood pressure include sleep apnea; certain medications, such as asthma drugs and cold medications; thyroid disease; and chronic kidney disease. Women may develop hypertension if they are pregnant, taking hormone replacement therapy, or on birth control pills.

An Important Distinction

• Uncontrolled hypertension, according to the AHA, includes but is not synonymous with resistant hypertension, which involves high blood pressure that doesn't respond to normal modes of treatment.

Who Is Involved?

• The overall category of uncontrolled hypertension includes patients who have been diagnosed with high blood pressure but are not following doctor's orders to control it, undiagnosed hypertensives, and patients with resistant hypertension.

Causes of Uncontrolled Hypertension

• Common causes of uncontrolled hypertension include inadequate access to health care; failure to follow doctors' orders, often linked to an inability to afford medications; high blood pressure resistant to treatment; and age-related inattention to self care.

Breakdown by Gender

• A 2008 report in "Circulation" estimated that 22 percent of adult women and 17 percent of adult men suffer from uncontrolled hypertension.

Geographic Trends

• Majid Ezzati, the study's lead author, reported that the rate of uncontrolled hypertension was highest in the states of Alabama, Georgia, Louisiana, Mississippi, South Carolina and Texas, as well as the District of Columbia.