The prevalence of secondary causes of hypertension varies depending on the studied population. Data suggest that 10% of adults with hypertension have secondary causes, although this percentage likely is an underestimate. Current American College of Cardiology/American Heart Association guidelines recommend screening for secondary causes of hypertension in patients who are younger than 30.

In a cross-sectional study, investigators aimed to characterise the prevalence of secondary causes in 2,000 young adults (age, 18–40) with confirmed hypertension who were seen in French hypertension referral centers.

Key findings were as follows:

• Secondary hypertension was noted in 30% of patients overall. Notably, patients who were 30 to 40 years old were more likely to have secondary causes than were those who were 18 to 30 years old.

• Secondary hypertension was more common in women, patients with body-mass index ≤25 kg/m2, and those with diabetes.

• Among patients with secondary causes, more than half had primary aldosteronism, and 20% had renovascular hypertension.

Secondary causes for hypertension, particularly primary aldosteronism, remain underdiagnosed. Early detection is critical, as many secondary causes have targeted treatments which are different from standard first-line therapies.