High Diastolic Blood Pressure: Causes and Risk Factors

Understanding the role of aldosterone

Of course, more research is needed to overcome any study limitations – like better understanding how the link applies to older patients – and proving cause-and-effect, that it’s not just an association. But as weight increases, precipitating a hormonal imbalance, an increase in aldosterone could be at play in some cases of isolated diastolic hypertension.

Sometimes referred to as the “salt hormone” or “salt-retaining hormone,” aldosterone affects water retention and regulates blood pressure; and an increase in the hormone could raise just diastolic blood pressure, Koch says. Of course, over time, it’s likely both systolic and diastolic blood pressure will go up, he adds.

Accordingly, doctors stress that it’s important to focus on what causes hypertension of any kind, rather than a specific type – since systolic and diastolic are treated together (medications, for example, act on both, even if only one is high) and the causes tend to be the same.

Risk factors for high diastolic blood pressure

Besides obesity and smoking, risk factors for high diastolic blood pressure – and hypertension generally – include:

• A diet high in salt
• Not getting enough physical activity
• Heavy alcohol use
• Lack of sleep
• Medical conditions ranging from diabetes to kidney disease and hyperthyroidism
• Medications, from nonsteroidal anti-inflammatory drugs like ibuprofen to decongestants
• Chronic stress

“Your blood vessels … are a source of resistance to the blood flow through the body – just like a tube would be or your garden hose would be,” explains W. Robert Taylor, M.D., professor of medicine and director of the cardiology division at the Emory University School of Medicine.

“It’s thought that people with isolated diastolic hypertension have this increased constriction or tone of the blood vessels,” Taylor says. But whether certain hormones or proteins in the blood or something else is behind that isn’t entirely clear. “Hypertension is not a single disease – there’s not a single thing that causes high blood pressure. So people with isolated diastolic likely have increased tone from a variety of causes, and [what’s causing that is] really not well known.”

What are risks or complications associated with diastolic hypertension?

Medical experts who treat blood pressure are quick to point out that the same urgency given to treating isolated systolic hypertension is often not ascribed to addressing isolated diastolic hypertension – which, by definition and design, is always the lower number of the two. The cardiovascular effect is an area that is still being actively researched, with studies showing that for some it could be an underrated risk factor for cardiovascular disease.

“It is associated with increased cardiovascular risk,” Taylor says. “I think people don’t appreciate it as much because we tend to focus on the systolic numbers, because those numbers are bigger.”

When hypertension of any kind goes undetected or untreated, there can be dire and deadly consequences. For diastolic and systolic hypertension, that includes heart attack, stroke, kidney disease and kidney failure.

How can you prevent high diastolic blood pressure?

The primary approaches to keep diastolic blood pressure in check apply to avoiding all hypertension in general. That includes:

• Stay active: Get at least 150 minutes of moderate-intensity exercise, like brisk walking, weekly.
• Lose extra pounds. “Being overweight definitely increases the risk of diastolic hypertension,” Taylor reminds.
• Watch alcohol consumption.
• Stop smoking.
• Control your cholesterol to avoid buildup that causes narrowing and hardening of arteries.
• Treat medical conditions that may cause secondary hypertension. For example, hypothyroidism, low thyroid, is linked to a higher rate of diastolic hypertension, Taylor says.

What are the treatment options and when should you consult your doctor?

High blood pressure is commonly asymptomatic – at least at first – meaning you won’t know you have it unless you see a high reading.

That means regular doctor’s visits and getting your blood pressure checked at least once a year.

If you have a high reading, you’ll also want to monitor it at home. Monitoring at home with an independently validated blood pressure device could help you determine your average blood pressure.

Koch also recommends going further to determine if an underlying medical condition is to blame for high diastolic or systolic blood pressure. Report any concerns to your primary care doctor who can test hormone levels, for example, if overproduction of aldosterone – or what’s called primary aldosteronism – is suspected. You can also ask for a referral to an endocrinologist for further evaluation, Koch adds.

Often a combination of lifestyle changes and medication are recommended to treat hypertension. Whatever you do, just don’t wait to address it.

“Start early, because it’s the silent killer,” Koch reminds – and called that for a reason.