Dec
High blood pressure (hypertension) is typically influenced by various factors, such as age, genetics, obesity, diet, and physical activity. However, about 10% of individuals with high blood pressure have secondary hypertension, which is a result of an underlying condition or disease.
In most cases, secondary hypertension is linked to issues with the adrenal glands or the arteries that supply the kidneys. Identifying and treating the root cause can often lead to an improvement or resolution of elevated blood pressure. Certain groups of people are more likely to experience secondary hypertension, and these include:
1. Individuals who develop high blood pressure before the age of 30.
2. Those who have never had high blood pressure but develop it suddenly, typically after the age of 70.
3. People who experience a sudden increase in blood pressure after many years of stable hypertension that has been well controlled with medication.
4. Individuals with blood pressure readings above 130/80 mm Hg despite taking four or more medications.
If you fall into any of these groups, it may be wise to explore the possibility of secondary hypertension and seek appropriate medical evaluation and care.
Aldosterone overload
The primary cause of secondary hypertension is often hyperaldosteronism, a condition in which one or both adrenal glands produce an excessive amount of aldosterone. Aldosterone contributes to elevated blood pressure by instructing the kidneys to retain sodium and water, increasing blood volume. This condition is often associated with a benign (noncancerous) growth in one adrenal gland or bilateral adrenal hyperplasia, where both adrenal glands are overactive for unknown reasons.
Hyperaldosteronism is less common in younger individuals (group 1) and more prevalent in middle-aged individuals with poorly controlled blood pressure (group 4). While a low potassium level can serve as a potential indicator, it’s noteworthy that most people with hyperaldosteronism maintain normal potassium levels, according to Dr. Randall Zusman. If someone falls into the specified groups and experiences potential symptoms or risk factors, further evaluation for hyperaldosteronism may be advisable.
Narrowed kidney arteries
Renal artery stenosis, characterized by the narrowing of the arteries supplying blood to the kidneys, is another prevalent cause of secondary hypertension. This narrowing typically results from the accumulation of fatty plaque in the artery walls, a condition commonly observed in older individuals. However, it can also manifest in young women with an inherited condition known as fibromuscular dysplasia, characterized by an excessive growth of muscular tissue in artery walls. As a consequence, physicians are more inclined to consider renal artery stenosis as a potential cause of secondary hypertension in people belonging to groups 1, 3, and 4.
Less frequent causes of secondary hypertension encompass Cushing’s syndrome, arising from the overproduction of the stress hormone cortisol by the adrenal glands or prolonged use of steroid medications, as well as thyroid disorders affecting the production of thyroid hormones. Sleep apnea, a condition characterized by brief periods of breathing cessation during sleep, can also induce hormonal changes leading to elevated blood pressure. (For group 2, any of the aforementioned issues may contribute to secondary hypertension.)
Resistant hypertension
Secondary hypertension is prevalent among individuals with what is known as resistant hypertension, encompassing those in the fourth group and individuals who take three different blood pressure medications at their maximum tolerated doses yet still experience high blood pressure. Overall, around one in four people with resistant hypertension is found to have an identifiable secondary cause.
However, for many individuals with persistently high blood pressure, the contributing factor may not be an underlying disorder but rather lifestyle habits, notes Dr. Zusman. Often, these individuals fail to adhere to their prescribed medication regimen or consume excessive amounts of sodium, which can counteract the effects of many blood pressure drugs. Some may also take other medications or dietary supplements known to elevate blood pressure.
When lifestyle habits are ruled out, doctors will investigate potential secondary causes, employing physical examinations and specialized blood or imaging tests to identify them. It’s important to remember that high blood pressure typically presents with no symptoms, and secondary causes can affect anyone. Thus, regular blood pressure checks during healthcare visits are crucial, as emphasized by Dr. Zusman.
