DEAR MAYO CLINIC: At my last few visits to the doctor my blood pressure was high. What causes resistant hypertension, and how is it treated if medications aren’t working?
ANSWER: The benefits of treating high blood pressure are well-known. Keeping your blood pressure at optimal levels reduces the risk of damage to your blood vessels, which helps prevent conditions such as stroke, heart attack, coronary artery disease, heart failure, and worsening chronic kidney disease.
High blood pressure, or hypertension, is considered resistant when a person is taking a diuretic and two other blood pressure medications, and blood pressure remains high. Diuretics lower blood pressure by helping your kidneys get rid of the extra salt and water in your body. Resistant hypertension has several possible causes, including another underlying medical condition, but many of those causes are reversible.
First, it’s important to rule out external factors that can affect your blood pressure readings. About 15% to 30% of people with hypertension have what’s called “white coat hypertension,” which means that their blood pressure increases at their healthcare provider’s office but goes back down at home. Your healthcare provider may have you monitor your blood pressure at home for a more accurate estimate of your blood pressure.
It may also be that another condition, such as a hormone imbalance or problems with the blood supply to the kidneys, is causing your high blood pressure. In this case, diagnosing and treating the underlying problem usually helps improve your blood pressure. You may need to see a hypertension specialist to pinpoint the cause.
Your healthcare provider, in coordination with your pharmacist, also can assess whether your current blood pressure medications and doses are appropriate. Research indicates that only about half the people with resistant hypertension receive optimal treatment for high blood pressure.
A variety of drugs are available to treat high blood pressure. If you are taking a diuretic and your blood pressure remains high, your healthcare provider may recommend adding additional medications, such as angiotensin-converting enzyme, or ACE, inhibitors; beta blockers; calcium channel blockers; or others that can help lower blood pressure. In many cases, a change in the amount of blood pressure medication a person is taking — often an increase in the diuretic — can effectively treat resistant hypertension. For blood pressure medications to work best, carefully follow the directions for taking them. Ask your healthcare provider what to do if you miss a dose.
Certain sleep problems also may contribute to resistant hypertension. Some people with high blood pressure, particularly those who are overweight, can have disturbed breathing during sleep, and that may lead to resistant hypertension. If you are exceptionally tired during the day and you snore while sleeping, tell your healthcare provider.
It’s also important to remember that the lifestyle choices you make can significantly affect your blood pressure. Eating a healthy diet that includes lots of fruits and vegetables, along with limiting salt intake, often can help control blood pressure. Staying at a healthy weight, exercising, not smoking, and limiting the amount of alcohol that you drink are important self-care steps for people with high blood pressure.
It’s not uncommon for people with high blood pressure go through several medications and changes in medication dosages before blood pressure is well-controlled. You may need to monitor your blood pressure at home for some time to determine if a new medication is working. In most cases, a combination of medications and healthy lifestyle changes can keep blood pressure in check. — Sandra Herrmann, MD, Nephrology, Mayo Clinic, Rochester, Minnesota