Isolated Systolic Hypertension: When Only The Top Number is High

We often regard hypertension as having a high top number (systolic) and bottom number (diastolic). But, did you know that a reading where only the systolic number is high is also considered hypertension? Doctors call it isolated systolic hypertension (ISH), and it is the most common form of hypertension in people aged 65 and up.

Isolated Systolic Hypertension, Defined

Isolated systolic hypertension happens when the bottom number is below 80 mmHg, but the top number or systolic pressure is higher than 130 mmHg.

So, let’s say you have frequent readings along the lines of 133/65 mmHg, 140/70 mmHg, or 150/75 mmHg, then you might have isolated systolic hypertension.  

A paper published in The American Journal of Medicine called isolated systolic hypertension a “rapidly growing public concern,” and its management remains a challenge to practicing doctors.

Possible Causes 

Experts believe that ISH results from a combination of aging-related physiological changes and modifiable risk factors. Likewise, an underlying health condition might also lead to a high top number.

Below are the possible conditions that predispose you to develop isolated systolic hypertension:

Artery Stiffness or Heart Valve Problems 

Artery stiffness is common in people with atherosclerosis, a condition where the arteries become thick and narrow due to the buildup of fatty deposits.

On the other hand, a heart valve problem indicates an issue in at least one of the four valves. Valves are structures that keep the blood flowing in the right direction. Valve disease may interrupt the normal blood flow in the heart, resulting in problems over time.

The symptoms of atherosclerosis and heart valve disease may overlap. Consult your doctor if you experience:

• Chest pain
• Shortness of breath
• Weakness or fatigue

Obesity

Obesity points to having a body mass index (BMI) of 30 or greater. Learn more about BMI here. You can also use our BMI tool here:

Note that obesity alone is also a risk factor for many diseases, not just isolated systolic hypertension. People with obesity are also at a heightened risk of stroke and cardiovascular diseases.  

Diabetes 

Diabetes means you might have problems controlling your blood sugar levels. Like obesity, diabetes is also a risk factor for many diseases. Moreover, uncontrolled diabetes might also lead to various complications.

Learn more about diabetes, its type, symptoms, and treatment here.  

An Overactive Thyroid  

An overactive thyroid or hyperthyroidism is also a risk factor for isolated systolic hypertension. Untreated hyperthyroidism can cause the following symptoms: anxiety or nervousness, rapid or irregular heartbeat, and unexplained weight loss. 

When To Consult a Doctor

It’s crucial to set an appointment with your doctor when you consistently observe high top numbers and normal bottom numbers in your measurements. You see, long-standing isolated systolic hypertension increases your risk for stroke, cardiovascular diseases, and chronic kidney disease.

In other words, it’s important to monitor your blood pressure. Check your BP twice daily, preferably at the same time. You can check it before breakfast and then again in the evening before going to bed. Record your results and show them to your doctor.

Your doctor will most likely recommend lifestyle and dietary changes to control your blood pressure. Case in point: They might encourage you to lose weight or follow the DASH diet. They might also order antihypertensive medicines, such as calcium channel blockers, ACE inhibitors, or beta-blockers.

Key Takeaways

ISH occurs when your diastolic (bottom number) is lower than 80, but your systolic reading is higher than 130 mmHg. It’s common in people aged 65 and older and may be caused by a combination of physiological changes and modifiable risk factors. Underlying health problems, like obesity, diabetes, and hyperthyroidism, may also lead to isolated systolic hypertension.

Learn more about Hypertension here.