Why Your Blood Pressure Can Remain High On Medication

While blood pressure medication can drastically reduce your blood pressure over time, it can still remain above normal levels. Learn more about high blood pressure, medications commonly used to treat it, and why your blood pressure can stay high on medication. 

What is high blood pressure?

High blood pressure is a common condition in the US, affecting around 47% of the population.

Blood pressure is the amount of strain or force your blood puts on your blood vessels as it circulates throughout your body. Your heart beats continuously, and it takes large amounts of force to move blood from one area of your body to another.

When your blood pressure is higher than normal, it can put a lot of wear and tear on your blood vessels. This puts you at risk of other health conditions. 

How blood pressure is measured

Blood pressure measurements give two different numbers, systolic and diastolic blood pressure, both of which are measured in mm Hg (millimeters of mercury).

Systolic blood pressure, the top number, shows the amount of pressure placed on your blood vessels when your heart beats. Diastolic blood pressure, the bottom number, indicates the amount of pressure your blood puts on your blood vessels between beats.

A normal blood pressure reading is less than 120/80mm Hg, so lower than 120 for systolic and 80 for diastolic pressure. 

Blood pressure readings higher than 120/80mm Hg have the following categories:

  • Elevated blood pressure: 120–129 systolic but lower than 80 diastolic

  • High blood pressure, or hypertension stage 1: 130–139 systolic and 80–89 diastolic

  • High blood pressure, or hypertension stage 2: 140 or higher for systolic and 90 or higher for diastolic

  • Hypertensive crisis: 180 or higher for systolic and higher than 120 for diastolic

Your blood pressure readings can be influenced by many factors, such as exercise or exertion before the blood pressure reading, caffeine intake,¹ anxiety,² and more. However, it's still important to take your readings seriously if they are elevated.

If you get multiple readings that show you are in hypertension stage 1 or 2, make an appointment with your doctor.

If your blood pressure readings show that you are in hypertensive crisis, wait a few minutes then take another reading. Seek immediate medical care if it remains high. Blood pressure at this level can lead to immediate bodily harm, such as organ damage, so call 911 if you experience:

  • Chest pain

  • Shortness of breath

  • Blurred vision

  • Difficulty speaking

  • Confusion

Symptoms of high blood pressure

Many people with slightly high blood pressure won't have any noticeable symptoms, but some may experience nosebleeds, shortness of breath, and headaches.

These symptoms aren't usually specific enough to lead people to talk to their doctor about high blood pressure. It often goes undiagnosed and untreated until it becomes serious enough to cause more obvious symptoms.

When blood pressure reaches an extremely high level, common symptoms include:

  • Fatigue 

  • Confusion

  • Irregular heartbeat

  • Difficulty breathing

  • Vision issues

  • Blood in urine

Causes of high blood pressure

High blood pressure is commonly associated with poor lifestyle habits. While it's certainly true that an unhealthy lifestyle increases your risk of developing the condition, there are dozens of other potential causes of high blood pressure. Researchers are constantly learning new things about the condition.

Some common causes of high blood pressure include:

Lifestyle factors

Diets high in sodium³ are strongly associated with high blood pressure. Most Americans ingest too much sodium, as they tend to consume plenty of fast food, convenience meals, and snacks with high sodium content.

People with high blood pressure caused by their lifestyle can greatly benefit by following the DASH (Dietary Approaches to Stop Hypertension) diet. The DASH eating plan⁴ encourages plenty of:

  • Fruit and vegetables

  • Whole grains

  • Low-fat dairy products

  • Fish

  • Beans

  • Nuts

  • Vegetable oils

It also recommends limiting foods high in saturated fats, like full-fat dairy products and fatty meats, as well as those high in sugar. Following the DASH diet doesn't mean giving up your favorite foods forever, just focusing on more nutrient-dense foods. 

Not getting enough exercise can also put you at risk of developing high blood pressure, as can high amounts of stress. The good news is that exercise can help relieve stress to some degree, so being active can help prevent high blood pressure by tackling both issues at once. Aim for 150 minutes of moderate physical activity or 75 minutes of vigorous activity per week. 

Smoking and drinking excessive alcohol can also contribute to high blood pressure. Having a drink or two occasionally is unlikely to produce negative health consequences, but excessive drinking can substantially raise a person's blood pressure over time. If you smoke, talk to your doctor about methods for quitting. 

Family history

High blood pressure can run in families, so if other people in your family have the condition, you are more likely to develop it.

However, just because you have many relations with hypertension, it doesn't mean you are doomed to get it. Healthy lifestyle habits and close monitoring can help keep your blood pressure in check. 

Age

As people age, they become more likely to develop high blood pressure. Slightly elevated blood pressure isn’t always a cause for concern in older adults, as it is common for a person's blood vessels to stiffen as they get older.

Older adults also tend to take more medication and have other chronic conditions that can also lead to high blood pressure.

Medications

Some medications are known to increase blood pressure, including:

  • Some oral birth control pills

  • Antidepressants

  • Cold medicines

  • Pain medicines

  • Immunosuppressants

Some supplements, like ginseng, licorice, and guarana can also cause high blood pressure, as can certain illegal drugs. If you take any of these substances, be sure to regularly monitor your blood pressure and see a healthcare professional for a physical checkup at least once a year.

Chronic conditions

Sometimes high blood pressure is caused by the presence of other chronic conditions, such as:

If you have any of these conditions, your doctor is likely already monitoring your blood pressure. Continue to get it checked regularly to ensure that it stays at healthy levels.

Medications for high blood pressure

There are a few medications that can help bring blood pressure back down to normal levels. It can take some time to find the right one.

Some of the most common medications for high blood pressure include:

Diuretics

Also known as ‘water pills’, diuretics can help reduce blood pressure by increasing the amount of water and sodium your kidneys expel through your urine. This reduces the amount of fluid circulating in your blood, thereby lowering blood pressure.

The main side effect of diuretics is increased urination, which can also lead to low potassium levels over time. Some diuretics, called ‘potassium-sparing diuretics’, can prevent potassium loss. 

ACE inhibitors

ACE (angiotensin-converting enzyme) inhibitors are another medication commonly prescribed for high blood pressure. These medications relax your blood vessels by preventing your body from producing angiotensin II, thereby lower blood pressure.

Angiotensin II narrows your blood vessels, which makes your heart work harder and raises blood pressure. Some common side effects include:

  • Fatigue

  • Dizziness

  • Loss of taste

  • Headaches

ARBs

ARBs (angiotensin II receptor blockers) also reduce blood pressure by relaxing your blood vessels. They prevent angiotensin II from narrowing blood vessels. This medication can cause:

  • Dizziness

  • High potassium levels

  • Angioedema (fluid buildup)

How long does it take for blood pressure medication to work?

The good news about blood pressure medications is that they tend to help lower your blood pressure quickly, often in as little as a few days.

Some people may have trouble getting used to having lower blood pressure, so they may feel excessively tired for a week or two after starting their medication.

It's important to take your blood pressure medication every day and to continue taking it even if your blood pressure has begun to drop. It can be dangerous to stop taking blood pressure medication without first talking to your doctor. 

Why blood pressure can remain high despite medication

Sometimes high blood pressure can be resistant to medication at first, especially if your doctor is experimenting with medication types and doses. It can take some trial and error to determine which type of medication works best for you, and which dose is most effective since everyone is different.

Some people may continue to struggle with high blood pressure even after trying numerous medication options and doses. This is commonly regarded as resistant high blood pressure. 

A person has resistant high blood pressure if all three of the following are true:

  • They take three different blood pressure medications

  • One medication is a diuretic

  • Their blood pressure remains above their goal

Approximately 20% of people with high blood pressure are resistant, which can result in uncontrolled high blood pressure. This can substantially increase a person's risk of:

  • Heart attacks

  • Strokes

  • Vision problems

  • Kidney damage

  • Memory impairment

  • Erectile dysfunction

Treatment for resistant high blood pressure

If medications don't lower a person's blood pressure to the desired level, there are three main treatments to address the issue:

Lifestyle

Those with resistant high blood pressure will likely have to undergo significant lifestyle changes to bring their blood pressure down to healthy levels. As mentioned above, some key lifestyle interventions include:

  • DASH eating plan

  • Regular exercise

  • Quitting smoking

  • Reducing alcohol consumption

  • Reducing stress

Your doctor can offer advice or referrals to help you address the lifestyle factors that may be contributing to your resistant high blood pressure.

Adjusting medications

Sometimes, resistant high blood pressure is simply caused by not having the right combination of medications at the right dosage. Your doctor may try changing one or more of your medications, or adjusting the dosage. They will closely monitor your blood pressure over time to see if these adjustments work, and continue to try different combinations until they find the right one.

Constantly changing medications and dosage can be a frustrating process, but it's important to take your medications as directed by a qualified healthcare professional. Don’t adjust the dosage yourself without professional advice.

Addressing chronic conditions 

Other conditions like diabetes and kidney disease can significantly increase blood pressure. Blood pressure medications aren't likely to help much if those initial conditions aren't also properly treated.

Lifestyle changes can also help with other chronic diseases, but your doctor may also have to adjust medications related to the initial condition.

The lowdown

It's not fun to receive a diagnosis of high blood pressure, and it can be scary to have high blood pressure that doesn't respond to medications right away.

Fortunately, several factors within your control can help improve your blood pressure over time, and your doctor will do everything they can to bring your blood pressure back down to a healthy level.

It may feel overwhelming to adjust your lifestyle habits, but tiny changes can add up over time. Including an extra serving of fruit or vegetables in your day, going for a short walk after work, or cutting down on your alcohol consumption by a drink or two at the start can help get you on the right track toward reducing your blood pressure and living a healthier life.

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