To diagnose secondary hypertension, your doctor will first take a blood pressure reading using an inflatable cuff, just as your blood pressure is measured during a typical doctor's appointment.
Your doctor may not diagnose secondary hypertension based on only one higher than normal blood pressure reading. It may take three to six high blood pressure measurements at separate appointments to diagnose secondary hypertension. These measurements may come from home blood pressure monitoring and ambulatory blood pressure monitoring. With ambulatory blood pressure monitoring, a device takes blood pressure measurements automatically at specific times throughout the day.
Your doctor will also want to check other markers to pinpoint the cause of your high blood pressure. These could include:
- A blood test. Your doctor may want to check your potassium, sodium, creatinine, fasting blood glucose, total cholesterol and triglycerides, and other chemicals in your blood to help make a diagnosis.
- A urine test. Your doctor may want to check your urine for markers that could show your high blood pressure is caused by another medical condition.
Ultrasound of your kidneys. Since many kidney conditions are linked to secondary hypertension, your doctor may order an ultrasound of your kidneys and blood vessels.
In this noninvasive test, a technician will run an instrument called a transducer over your skin. The transducer, which produces sound waves, measures how the sound waves bounce off your kidneys and arteries and sends images created by the sound waves to a computer monitor.
Electrocardiogram (ECG). If your doctor thinks your secondary hypertension may be caused by a heart problem, he or she may order an electrocardiogram.
In this noninvasive test, sensors (electrodes) that can detect the electrical activity of your heart are attached to your chest and sometimes to your limbs. An ECG measures the timing and duration of each electrical phase in your heartbeat.
Often, an underlying medical condition requires treatment with medications or surgery. Once an underlying condition is effectively treated, secondary hypertension may decrease or even return to normal.
Often, however, lifestyle changes — such as eating healthy foods, increasing physical activity and maintaining a healthy weight — can help keep your blood pressure low. You may need to continue to take blood pressure medication as well, and any underlying medical condition you have may affect your doctor's choice of medication.
Possible drug choices include:
Thiazide diuretics. Diuretics, sometimes called water pills, are medications that act on your kidneys to help your body eliminate sodium and water, reducing blood volume. Thiazide diuretics are often the first — but not the only — choice in high blood pressure medications.
These medications 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 doctor about adding one or replacing a drug you currently take with a diuretic. Possible side effects include weakness, leg cramps and a higher risk of sexual dysfunction.
Beta blockers. These medications reduce the workload on your heart and open your blood vessels, causing your 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. In addition, beta blockers generally aren't prescribed 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, and these medications aren't recommended during pregnancy.
Angiotensin II receptor blockers. These medications help relax blood vessels by blocking the action — not the formation — 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, but are also not used during pregnancy.
Calcium channel blockers. These medications help relax the muscles of your blood vessels or slow your 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 blood levels of the medication and putting you at higher risk of side effects. Ask your doctor or pharmacist if your medication is affected by grapefruit juice.
Direct renin inhibitors. Newer treatments for hypertension include direct renin inhibitors, such as aliskiren (Tekturna™). Aliskiren relaxes and widens the arteries by preventing the action of renin. Renin is the initial enzyme in a cascade of steps in the production of chemicals (angiotensin, aldosterone, others) important in cardiovascular health and disease.
The Food and Drug Administration strongly cautions against using aliskiren in combination with ACE inhibitors or angiotensin II receptor blockers in people with diabetes or moderate to severe kidney problems. Common side effects of aliskiren include dizziness and diarrhea.
Treatment can sometimes be complicated. You may need more than one medication combined with lifestyle changes to control your high blood pressure. And your doctor will want to see you more frequently until your blood pressure is stabilized, possibly as frequently as once a month. Your doctor may also recommend that you keep track of your blood pressure at home.
Lifestyle and home remedies
Although lowering secondary hypertension can be difficult, making the same lifestyle changes you would make if you had primary high blood pressure can help. These include:
- Eat 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.
Decrease the salt in your diet. A lower sodium level — 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.
While you can reduce the amount of salt you eat by putting down the saltshaker, you should also pay attention to the amount of salt that's in the processed foods you eat, such as canned soups or frozen dinners.
- Maintain a healthy weight. If you're overweight, losing even 10 pounds (4.5 kilograms) can lower your blood pressure.
- Increase physical activity. Regular physical activity can help lower your blood pressure and keep your weight under control. Strive for at least 30 minutes of physical activity a day.
- Limit alcohol. Even if you're healthy, alcohol can raise your blood pressure. If you choose to drink alcohol, do so in moderation — up to one drink a day for women and two drinks a day for men aged 65 or younger. For men and women 65 years old or older, stick to one drink a day.
- Don't smoke. Tobacco injures blood vessel walls and speeds up the process of hardening of the arteries. If you smoke, ask your doctor to help you quit.
- Manage 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
Your high blood pressure may be discovered during a routine physical. At that point, your primary care doctor may order more tests or refer you to a doctor who specializes in treating whatever the suspected underlying cause of your high blood pressure may be. For example, if your doctor 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).
Because appointments can be brief, and there's often a lot to cover, it's a good idea to arrive well-prepared. Here's some information to help you get ready for your appointment, and what to expect from your doctor.
What you can do
- Be aware of any pre-appointment restrictions. At the time you make the appointment, be sure to 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 any symptoms you're experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment.
- Write down key personal information, including any major stresses or recent life changes.
- Make a list of all medications, vitamins or supplements that you're taking, as well as information on the dose you take for each.
- Write down questions to ask your doctor.
Your time with your doctor may be limited, so preparing a list of questions can help you make the most of your time together. For secondary hypertension, some basic questions to ask your doctor include:
- What do you think is causing my high blood pressure?
- What kinds of tests do I need? Do these tests require any special preparation?
- Is my high blood pressure temporary or long lasting?
- What treatments are available for the cause of my high blood pressure and which do you recommend?
- What types of side effects can I expect from treatment?
- I have other health conditions. How can I best manage these conditions together?
- Are there any dietary or activity restrictions that I need to follow?
- What types of lifestyle changes can I make on my own that might help lower my blood pressure?
- Is there a generic alternative to the medicine you're prescribing for me?
- 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 any brochures or other printed material that I can take home with me? What websites do you recommend visiting?
In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment.
What to expect from your doctor
Your doctor is likely to ask you a number of questions. Being ready to answer them may reserve time to go over any points you want to spend more time on. Your doctor may ask:
- Has anyone in your family ever been diagnosed with high blood pressure?
- If yes, do you know if there was an underlying reason for the high blood pressure? For example, does your relative have diabetes or kidney problems?
- Have you experienced any unusual symptoms?
- How much salt is in your diet?
- Has your body weight changed recently?
- If you were ever pregnant, was your blood pressure elevated during pregnancy?