If you’ve been diagnosed with obesity, there’s a good chance you may also have hypertension (high blood pressure), a common condition that affects almost 50 percent of U.S. adults. Although many people know they have high blood pressure, others may not, because the condition often has no noticeable symptoms.

If you or someone you love is a larger-bodied person who also has high blood pressure, you may wonder if these two conditions are related.

This article discusses how obesity and high blood pressure are related — and how weight loss may help reduce blood pressure.

Obesity vs. High Blood Pressure

The term “obesity” refers to having an excess of adipose tissue (body fat), which can harm your health. Obesity is often diagnosed by calculating a person’s body mass index (BMI) — body weight divided by height — but this isn’t always an accurate way to assess health. People with the same BMI can have very different body compositions and health risks.

Blood pressure — how hard your blood pushes against your artery walls — is another important measure of health. High blood pressure is defined as 130/80 millimeters of mercury (mm Hg) or more. The first number, called systolic pressure, measures the force of blood when your heart beats. The second number, diastolic pressure, measures the pressure in between heartbeats.

There are two types of high blood pressure. Most adults with high blood pressure have primary hypertension — also called essential hypertension — which has no clear cause. Secondary hypertension occurs when high blood pressure is caused by another health issue, such as kidney disease.

Are Obesity and High Blood Pressure Related?

Research shows a strong connection between BMI and blood pressure. The Framingham Heart Study, a well-known study that started in 1948, found that obesity was the main cause of high blood pressure in 65 percent to 78 percent of adults with primary hypertension.

Since then, obesity prevalence (the number of people diagnosed with obesity) has more than doubled, so it’s not surprising that more people are also experiencing obesity-related hypertension.

Recent studies show that about 36 percent to 47 percent of people with obesity also have high blood pressure. In comparison, about 20 percent with a BMI in the “normal” range have high blood pressure.

How Does Obesity Lead to High Blood Pressure?

Obesity can affect blood pressure in several ways. Two key systems — the sympathetic nervous system (SNS) and the renin-angiotensin-aldosterone system (RAAS) — play major roles, as do certain hormones.

Sympathetic Nervous System

The SNS is a network of nerves that controls automatic body functions, like heart rate and blood pressure. For example, the SNS controls the fight-or-flight response, which kicks in when you’re stressed or in danger.

Researchers have reported that people with obesity have an overactive SNS, especially in the muscles and kidneys. This extra activity can drive up blood pressure.

More evidence of this connection is that certain medications that block stress hormones — like alpha-blockers and beta-blockers — tend to lower high blood pressure more effectively in people with obesity than in people with lower body weights.

Renin-Angiotensin-Aldosterone System

The RAAS helps regulate blood pressure and the volume of fluid in the body. The RAAS keeps blood pressure steady by tightening blood vessels and helping the body hold on to water and sodium (salt). This system includes an enzyme called renin and two hormones — angiotensin II and aldosterone.

Studies have shown that people diagnosed with obesity have elevated amounts of the enzymes and hormones that make up RAAS. When this system is activated, it releases more hormones that make blood vessels narrower and signal the kidneys to hang on to extra salt and water. This raises blood pressure and increases the risk of hypertension.

Leptin

Leptin, a hormone made by fat cells, helps to control hunger and balance energy. This hormone also can activate the sympathetic nervous system and raise blood pressure.

Normally, leptin reduces hunger and helps the body use more energy. However, people with obesity may have leptin resistance — they may have high leptin levels, but the hormone doesn’t do its usual job of reducing hunger and boosting metabolism.

However, leptin can still overstimulate the SNS, which may help explain why high leptin levels in people with obesity are linked to higher blood pressure.

Insulin

Insulin is a hormone made by the pancreas that helps the body turn glucose (sugar) into energy. Both insulin resistance and increased levels of insulin in the blood have been linked to obesity. Insulin problems can affect blood pressure in several ways:

• Extra insulin can stimulate the SNS, which raises blood pressure.
• Insulin resistance can cause the kidneys to hold on to more salt, raising blood pressure.
• Insulin usually helps blood vessels relax and widen, but this doesn’t happen in people with obesity. Instead, vascular dysfunction (when blood vessels don’t work as they should) leads to narrower vessels and higher blood pressure.

Does Belly Fat Cause High Blood Pressure?

Belly fat — also called visceral adipose tissue — is linked to heart health and high blood pressure. Visceral fat is the type of fat that wraps around internal organs and sits deep inside the abdomen. Body fat carried in the belly may raise your risk of high blood pressure in a few key ways.

Fat distribution in your midsection can press on the kidneys, reducing blood flow and making it harder for these organs to get rid of extra salt. When the kidneys hold on to more salt, blood pressure rises. Over time, the kidneys become damaged and don’t filter salt as well, further increasing blood pressure.

Belly fat has also been shown to overstimulate the sympathetic nervous system. When the SNS is constantly activated, it can raise blood pressure and keep it elevated over time.

Can Losing Weight Reduce Blood Pressure?

Weight loss is one of the most effective ways to improve blood pressure. However, keeping weight off long term can be challenging, because it usually requires ongoing changes to diet and activity levels.

Weight-loss efforts can also be complicated by other factors, such as genetics. One study showed that certain genes may make people more likely to regain weight or have a harder time losing weight in the first place.

Lifestyle Changes

Healthy lifestyle changes, like eating a balanced diet and getting regular physical activity, can help lower blood pressure and improve related issues like insulin resistance. One large study looked at various diets and found that following certain eating patterns, including the Mediterranean, Nordic, and Dietary Approaches to Stop Hypertension (DASH) diets, reduced blood pressure in adults. The DASH diet was also linked to reduced activity in the sympathetic nervous system.

That said, many people lose weight at first with lifestyle changes but gain it back if they don’t keep up those habits.

Weight-Loss Medications

Several prescription medications are now approved to help with weight loss — and some may also help lower blood pressure. For example:

• Orlistat and phentermine/topiramate have been shown to reduce both weight and blood pressure.
• Naltrexone/bupropion also supports weight loss, but its effects on blood pressure are less clear.
• Tirzepatide has shown promise in reducing both weight and blood pressure in people with obesity.

However, because these drugs are new, long-term effects on blood pressure aren’t yet known.

Bariatric Surgery

People who have trouble maintaining weight loss with lifestyle changes may consider undergoing bariatric (metabolic) surgery. These procedures change parts of the digestive system to help people lose weight.

Combined with lifestyle changes, bariatric surgery can be an effective way to lose weight and lower blood pressure. It’s also an option for lowering blood pressure in people who have resistant hypertension — high blood pressure that doesn’t respond well to medications.

One study found that people with obesity lost around 57 more pounds with bariatric surgery compared to nonsurgical treatments.

Another large study of almost 1,400 adults with obesity and high blood pressure found that those who had bariatric surgery were:

• Almost three times more likely to reduce their blood pressure to under 140/90 mm Hg
• Seven times more likely to lower it below 130/80 mm Hg
• More likely to reduce their blood pressure medications

While these results are promising, more research is still needed to fully understand how bariatric surgery affects blood pressure in the long run.

If you’re interested in learning more about weight-loss options — including medications or bariatric surgery — talk to your healthcare provider. Together, you can find the approach that’s right for you.

Talk With Others Who Understand

MyObesityTeam is the social network for people with obesity and their loved ones. On MyObesityTeam, more than 56,000 members come together to ask questions, give advice, and share their stories with others who understand life with obesity.

Have you been diagnosed with high blood pressure and obesity? What lifestyle changes do you use to manage these conditions? Share your comments below, start a conversation by posting on your Activities page, or connect with like-minded members in Groups.