To diagnose secondary hypertension, a health care provider will take a blood pressure reading using an inflatable cuff.
A care provider might not diagnose secondary hypertension based on a single high blood pressure reading. It may take 3 to 6 high blood pressure measurements at separate appointments to diagnose secondary hypertension. Home blood pressure monitoring and ambulatory blood pressure monitoring might make up some of these readings. With ambulatory blood pressure monitoring, a device takes blood pressure measurements automatically at specific times throughout the day.
Other tests to help pinpoint the cause of the high blood pressure might include:
- Blood tests. Blood tests are often done to check levels of potassium, sodium, creatinine, blood glucose, and total cholesterol and triglycerides, among others.
- A urine test (urinalysis). A urine sample can contain markers that could point to medical conditions that cause high blood pressure.
- Ultrasound of the kidneys. Many kidney conditions are linked to secondary hypertension. In this noninvasive test, a technician moves a small, hand-held device called a transducer over the area to be tested. The transducer sends sound waves into the body, collects the ones that bounce back and sends them to a computer. The computer then creates images of the kidneys.
Electrocardiogram (ECG or EKG). This painless noninvasive test records the electrical signals in the heart. This test can help determine whether a heart problem might be causing secondary hypertension.
In this test, sensors (electrodes) are attached to the chest and sometimes to the limbs. The sensors connect to a computer that records the heart's electrical signal information and displays it as waves on a monitor or on paper. This test shows how the heart is beating.
Treatment for secondary hypertension involves treating the medical condition that's causing it with medications or surgery. Once the condition is treated, blood pressure might decrease or return to normal.
Treatment might require continuing to take blood pressure medication, as well. The underlying medical condition might affect this choice of medication.
Possible drug choices include:
Thiazide diuretics. Diuretics, sometimes called water pills, are medications that help kidneys eliminate sodium and water. Thiazide diuretics are often the first — but not the only — choice in high blood pressure medications.
Diuretics are often generic and tend to be less expensive than other high blood pressure medications. If you're not taking a diuretic and your blood pressure remains high, talk to your provider about adding one or replacing a drug you take with a diuretic. Possible side effects of diuretics include weakness, leg cramps and a higher risk of having sexual issues.
Beta blockers. These medications reduce the workload on the heart and open the blood vessels. This causes the heart to beat slower and with less force. When prescribed alone, beta blockers don't work as well in Black people — but they're effective when combined with a thiazide diuretic.
Possible side effects include fatigue, sleep problems, a slowed heart rate, and cold hands and feet. Beta blockers generally aren't used for people with asthma, as they can increase muscle spasms in the lungs.
Angiotensin-converting enzyme (ACE) inhibitors. These medications help relax blood vessels by blocking the formation of a natural chemical that narrows blood vessels. ACE inhibitors may be especially important in treating high blood pressure in people with coronary artery disease, heart failure or kidney failure.
Like beta blockers, ACE inhibitors don't work as well in Black people when prescribed alone, but they're effective when combined with a thiazide diuretic. Possible side effects include dizziness and coughing. ACE inhibitors should not be taken during pregnancy.
Angiotensin II receptor blockers. These medications help relax blood vessels by blocking the action of a natural chemical that narrows blood vessels. Like ACE inhibitors, angiotensin II receptor blockers often are useful for people with coronary artery disease, heart failure or kidney failure.
These medications have fewer potential side effects than do ACE inhibitors. Angiotensin II receptor blockers should not be used during pregnancy.
Calcium channel blockers. These medications help relax the muscles of the blood vessels or slow the heart rate. Calcium channel blockers may work better for some people than ACE inhibitors or beta blockers alone. Possible side effects include water retention, dizziness and constipation.
Grapefruit juice interacts with some calcium channel blockers, increasing levels of the medication in the blood and increasing the risk of side effects. Ask your health care provider or pharmacist if grapefruit juice affects your medication.
Direct renin inhibitors. These medications relax and widen the arteries by preventing the action of a protein (enzyme) called renin. An example of a direct renin inhibitor is as aliskiren (Tekturna).
Common side effects of aliskiren include dizziness and diarrhea. People with diabetes or moderate to severe kidney problems shouldn't use aliskiren in combination with ACE inhibitors or angiotensin II receptor blockers.
Treatment for secondary hypertension can sometimes be complicated. It might take more than one medication combined with lifestyle changes to control high blood pressure. Your health care provider will want to see you more often — possibly as often as once a month — until your blood pressure is controlled. Your provider may also recommend that you keep track of your blood pressure at home.
Lifestyle and home remedies
Healthy lifestyle changes are recommended to keep the heart healthy and blood pressure low. These include:
- Eating healthy foods. Try the Dietary Approaches to Stop Hypertension (DASH) diet, which emphasizes fruits, vegetables, whole grains and low-fat dairy foods. Get plenty of potassium, which is found in fruits and vegetables such as potatoes, spinach, bananas and apricots, to help prevent and control high blood pressure. Eat less saturated fat and total fat.
Decreasing salt in the diet. A lower sodium intake — 1,500 milligrams (mg) a day — is appropriate for people 51 years of age and older and for people of any age who are Black or who have hypertension, diabetes or chronic kidney disease. Otherwise healthy people can aim for 2,300 mg a day or less.
Reducing salt requires putting down the saltshaker and paying attention to the amount of salt in processed foods, such as canned soups or frozen dinners.
- Maintaining a healthy weight. If you're overweight, losing even 10 pounds (4.5 kilograms) can lower your blood pressure.
- Increasing physical activity. Regular physical activity can help lower blood pressure and keep weight under control. Strive for at least 30 minutes of physical activity a day.
- Limiting alcohol. Even if you're healthy, alcohol can raise your blood pressure. If you choose to drink alcohol, do so in moderation. For healthy adults, that means up to one drink a day for women and two drinks a day for men.
- Not smoking. Tobacco injures blood vessel walls and speeds up the process of hardening of the arteries. If you smoke, ask your health care provider to help you quit.
- Managing stress. Reduce stress as much as possible. Practice healthy coping techniques, such as muscle relaxation and deep breathing. Getting plenty of sleep can help, too.
Preparing for your appointment
High blood pressure may be discovered during a routine physical. At that point, your primary care provider may order more tests or refer you to a provider who specializes in treating the suspected cause of your high blood pressure. For example, if your provider believes that a kidney problem is causing your high blood pressure, you'll likely be referred to a doctor who specializes in treating kidney disorders (nephrologist).
Here's some information to help you get ready for your appointment.
What you can do
- Be aware of any pre-appointment restrictions. When you make the appointment, ask if there's anything you need to do in advance, such as restrict your diet for a certain number of hours before your appointment.
- Write down your symptoms, including any that may seem unrelated to the reason for which you scheduled the appointment, and when they began.
- Write down key personal information, including major stresses or recent life changes.
- Make a list of all medications, vitamins or supplements you take, including doses.
- Write down questions to ask your provider.
For secondary hypertension, some basic questions to ask include:
- What do you think is causing my high blood pressure?
- What tests do I need? Do these tests require any special preparation?
- Is my high blood pressure temporary or long lasting?
- I have other health conditions. How can I best manage these conditions together?
- Are there dietary or activity restrictions that I need to follow?
- How often do I need to come back to have my blood pressure checked?
- Do I need to check my blood pressure at home? If so, how often?
- Which type of blood pressure machine is best? Can you help me learn how to use it correctly?
- Are there brochures or other printed material that I can have? What websites do you recommend?
Don't hesitate to ask other questions.
What to expect from your doctor
Your provider is likely to ask you questions, including:
- Has anyone in your family ever been diagnosed with high blood pressure?
- If yes, do you know the reason for the high blood pressure? For example, does your relative have diabetes or kidney problems?
- Have you had unusual symptoms?
- How much salt is in your diet?
- Has your body weight changed recently?
- If you were ever pregnant, was your blood pressure higher during pregnancy?