Hypertension, or high blood pressure, is an increasingly common condition, affecting almost half of all U.S. adults. Unfortunately, hypertension can cause a range of life-threatening conditions if left untreated. Hypertension comes in many forms that pose several challenges to effective management.

Keep reading to learn more about different types of hypertension, what causes them and how to treat them.

What is Hypertension?


Hypertension is a condition where blood pressure is too high. Blood pressure refers to the force put on arteries and veins caused by blood pumped from the heart. Over time, the excess force can cause damage to veins and arteries, making it harder to carry oxygen-rich blood around the body. Left untreated, hypertension can lead to an increased risk of heart disease, stroke and early death.

To make matters worse, hypertension doesn’t typically cause any symptoms, so people often don’t get the treatment they need. That’s why hypertension has been referred to as the “silent killer.” As a result of its zero-symptom status, almost half a million people a year have hypertension as either a leading or secondary cause of death.

A healthy blood pressure level is usually around 120/80 mmHg or less. According to the American College of Cardiology and the American Heart Association, general hypertension is diagnosed in someone with a blood pressure measurement of 130/80 mmHg or higher.

High blood pressure research shows that several factors can contribute to the development of hypertension. These factors include lifestyle habits (such as eating foods high in salt and cholesterol), chronic conditions (such as diabetes or primary aldosteronism), family history or genetics. In addition, clinical trials have also shown that medications like oral contraceptives can cause hypertension in women.

Treatment-Resistant Hypertension

What is Treatment-Resistant Hypertension?

Treatment-resistant hypertension is usually diagnosed in people taking at least three medications to control their hypertension but are unable to control of their high blood pressure. Blood pressure levels remain high and above patient goal levels. One of these medications is usually a thiazide diuretic, which helps the body shed excess salt and water in order to lower blood pressure. Some hypertensive patients may also be considered treatment-resistant if they can lower their blood pressure to a healthy level but require four or more medications to do so.

It’s estimated that about 489 million patients are being treated with antihypertensive agents globally. However, about 297 million of these patients are unable to achieve blood pressure control, putting them at increased risk for cardiovascular complications.


What are the Causes of Treatment-Resistant Hypertension

Secondary hypertension (hypertension caused by an underlying health condition) is one of the more common reasons people develop treatment-resistant hypertension. This is different than essential hypertension, which is more likely caused by factors such as lifestyle habits (including diets high in sodium).


Some of the most common underlying health conditions that are considered risk factors for hypertension include obstructive sleep apnea (blocked airflow while sleeping), renal artery stenosis (a narrowing of arteries that carry blood to the kidneys) diabetes and primary aldosteronism. Treatment-resistant hypertension can also cause chronic kidney disease or make it worse.

Certain conditions affect organ function (such as renal artery stenosis) by damaging blood vessels, limiting blood flow and causing a rise in blood pressure. Conditions like primary aldosteronism change how the body produces hormones like aldosterone, which can directly affect blood pressure.

CinCor is conducting several clinical trials exploring a potential new treatment option, baxdrostat, for adults with hypertension caused by the overproduction of aldosterone.

Other causes of secondary hypertension include:

  • Plaque buildup in veins and arteries (coronary artery disease)
  • Obesity, poor diet and alcohol consumption
  • Old age

Diagnosing treatment-resistant hypertension is challenging. In some cases, white coat hypertension, or hypertension that fluctuates when someone is in a stressful situation (such as talking with a doctor in a “white coat”), can skew readings. In addition, some patients may show lower blood pressure after leaving a clinical setting or while moving around, which is called ambulatory hypertension.

Ultimately, many conditions can cause treatment-resistant hypertension, but accurately measuring blood pressure is key to making an accurate diagnosis.


How is Treatment-Resistant Hypertension Treated?

Management and treatment of treatment-resistant hypertension may sound challenging, especially for people with hypertension caused by an underlying health concern. In their case, they need to address both the underlying health condition and the hypertension it causes. If the underlying cause of hypertension can’t be identified, patients may start to feel frustrated when their medications are not helping lower their blood pressure.

A common first step for treatment-resistant hypertension is to add a new blood pressure medication to a patient’s treatment regimen. A combination of medications can address multiple blood pressure pathways in the body, potentially improving the chances of lowering blood pressure.

CinCor is conducting several clinical trials to test baxdrostat for treatment-resistant hypertension, including the BrigHtn study.

Uncontrolled Hypertension

What is Uncontrolled Hypertension?

Like treatment resistant hypertension, uncontrolled hypertension refers to blood pressure that remains higher than goal levels despite patients taking medication or adhering to lifestyle modifications (such as dietary changes or reduced alcohol consumption). People with uncontrolled hypertension are typically on lifestyle modification and/or one or more medications (but less than three) and are not optimally treated for their hypertension.


What are the Causes of Uncontrolled Hypertension

The cause of uncontrolled hypertension, however, is often due to an inadequate level of treatment, inaccurate diagnoses and/or patients not correctly taking medications. Several scenarios can lead to patients not receiving the treatment they need.

For example, hypertension may be considered uncontrolled if a patient has only implemented lifestyle changes (such as changes to diet and exercise) without taking any medication, and their blood pressure levels remain at 140/90 mmHg or higher.

Patients may also have uncontrolled hypertension if they continue having high blood pressure after starting treatment (usually one or two medications).

Levels of patient adherence to medication regimens can also lead to uncontrolled hypertension. If patients do not take their medications as prescribed, their high blood pressure may continue.


How is Uncontrolled Hypertension Treated?

Depending on baseline blood pressure levels, treatment guidelines recommend the patient typically begin with lifestyle modifications. If blood pressure is not controlled after following lifestyle modifications, then medication may be prescribed. The most common treatments include thiazide diuretics, angiotensin convert enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), and calcium channel blockers (CCBs). If hypertension doesn’t respond to initial treatments and if lack of patient adherence is ruled out, a doctor may recommend adding a second-line therapy to a patient’s treatment regimen.

A doctor may also order tests to look for other conditions causing hypertension. These tests can help identify more targeted ways to treat a patient’s hypertension.

Refractory Hypertension

What is Refractory Hypertension?

Refractory (meaning resistant or stubborn) hypertension is a severe form of treatment-resistant hypertension. It is often characterized by people who have high blood pressure despite taking five or more medications at the maximum tolerable doses. Medications can include a mineralocorticoid receptor antagonist (MRA), such as spironolactone, commonly prescribed in patients diagnosed with treatment-resistant hypertension. People with refractory hypertension have nearly reached near-maximal medication dosages with no effect on their blood pressure.

People with refractory hypertension often experience more sympathetic nervous system activity. When active, the sympathetic nervous system can cause an increase in heart rate and cause blood vessels to constrict. It also has a connection to the regulation of blood pressure.

Refractory hypertension is quite rare, affecting only about 5% of hypertension patients.


What are the Causes of Refractory Hypertension?

Many causes of refractory hypertension overlap significantly with resistant hypertension. These causes include underlying health conditions such as diabetes and obesity. Refractory hypertension is also more common in women, younger adults and African Americans.


How is Refractory Hypertension Treated?

If medications have been unsuccessful up to this point, a doctor may perform additional tests to see if other conditions are causing a patient’s hypertension and treat that condition, if possible.