Secondary Hypertension

Hypertension is the most common risk factor for cardiovascular mortality and represents a major public health issue. In Turkey, the most recent study on hypertension, the PatenT-2 study, reported a prevalence of 30.3%. Although the most frequently encountered form is essential hypertension—of unknown cause and often associated with family history and obesity—secondary hypertension (SH) accounts for a significant proportion, ranging from 5% to 15%. Secondary hypertension refers to elevated blood pressure resulting from an identifiable underlying cause, and it may improve when the underlying condition is properly treated. When diagnosed and managed early, SH may be curable in some patients or lead to improved blood pressure control along with a reduction in cardiovascular disease risk.

Conditions Suggestive of Secondary Hypertension

Secondary hypertension should be suspected in the following situations:

• Stage 2 hypertension before the age of 40
  
• Onset during childhood
  
• Stage 3 hypertension presenting with a hypertensive emergency
  
• Resistant hypertension
  
• Target-organ damage disproportionate to the degree of hypertension
  
• Absence of family history of hypertension
  
• Family history of kidney disease
  
• Signs or symptoms suggesting chronic kidney disease
  
• Symptoms or family history of pheochromocytoma
  
• Obstructive sleep apnea
  
• Clinical findings suggesting endocrine causes

Medications That Elevate Blood Pressure

Many commonly prescribed medications have been associated with causing hypertension, worsening blood pressure control in hypertensive individuals, or reducing the effectiveness of antihypertensive medications. When an offending medication is identified, discontinuation, dose reduction, or switching to an alternative therapy is recommended whenever possible.

Frequently used medications associated with elevated blood pressure include:

• Non-opioid analgesics
  
• Nonsteroidal anti-inflammatory drugs (including aspirin)
  
• Selective COX-2 inhibitors
  
• Sympathomimetic agents (decongestants, diet pills, cocaine)
  
• Stimulants (methylphenidate, dexmethylphenidate, dextroamphetamine, amphetamine, methamphetamine, modafinil)
  
• Alcohol
  
• Oral contraceptives
  
• Cyclosporine
  
• Erythropoietin
  
• Natural licorice
  
• Herbal preparations (ephedra or ma huang)

Initial Evaluation

The initial evaluation includes confirming the accuracy of the hypertension diagnosis. Blood pressure must be measured using proper technique and should be elevated in at least two different readings across at least two separate visits. When necessary, 24-hour ambulatory blood pressure monitoring should be performed to assess for white coat hypertension or masked hypertension.

All patients diagnosed with hypertension should undergo routine laboratory testing. Abnormal results warrant further investigation. If no abnormalities are found but the patient exhibits signs suggestive of secondary hypertension—such as resistant or severe hypertension—age-appropriate and etiology-specific diagnostic tests should be planned.

Prognosis

In younger patients (<40 years), blood pressure may significantly improve following treatment of the specific underlying cause. However, in older individuals, improvement may be limited due to a 35% coexistence of essential hypertension and the irreversible vascular consequences of long-standing elevated blood pressure.