Secondary hypertension is high blood pressure with an identifiable cause. Often, the cause is a medical condition or a medication you’re taking. An underlying condition may cause symptoms, but it’s possible to have no symptoms at all. That’s why blood pressure checks are so important. Treating the cause may lower your blood pressure.

What Is Secondary Hypertension?

Secondary hypertension is high blood pressure that has a known cause. The cause might be another medical condition, or certain medicines or substances you’re using. Often, treating this underlying cause can reduce your blood pressure to healthier levels. Secondary hypertension is different than primary hypertension, which doesn’t have one distinct cause.

Most cases of hypertension are primary. Experts used to think that only 5% to 10% of high blood pressure cases have secondary causes. But recent research shows the actual number of secondary hypertension cases may be much higher. This is because many cases go unrecognized or are diagnosed as primary hypertension.

Symptoms and Causes

Secondary hypertension causes

The causes of secondary hypertension (from most to least common) include:

Medications that can raise your blood pressure include:

All medicines come with benefits and risks. If you think one of your medicines is raising your blood pressure, talk to a healthcare provider. Ask them if you should keep taking the medication.

Other substances that can cause secondary hypertension include:

Signs and symptoms of secondary hypertension

Secondary hypertension itself usually doesn’t have symptoms (unless your blood pressure is very high). But you may develop symptoms from the underlying condition that’s causing it.

The table below lists examples of symptoms you might have from various causes.

Possible symptomsCause of secondary hypertension
Increased sweating, hand tremors, feeling anxious or nervous, unexplained weight loss, fast heart rate, heart palpitationsHyperthyroidism
Fatigue, hoarseness, weight gain, muscle weakness, numbness in hands, brain fogHyperthyroidism
Waking often at night, pauses in breathing while you sleep, snoring, night sweats, daytime fatigue, mood changes, trouble concentratingObstructive sleep apnea
Fatigue, excessive thirst, peeing more than usual, headaches, muscle cramps or weakness, blurred visionPrimary aldosteronism
Confusion, trouble sleeping, edema, fatigue, headaches, loss of appetite, dry or itchy skin (these occur as the disease gets worse)Renal artery stenosis
Possible symptoms
Increased sweating, hand tremors, feeling anxious or nervous, unexplained weight loss, fast heart rate, heart palpitations
Cause of secondary hypertension
Hyperthyroidism
Fatigue, hoarseness, weight gain, muscle weakness, numbness in hands, brain fog
Cause of secondary hypertension
Hyperthyroidism
Waking often at night, pauses in breathing while you sleep, snoring, night sweats, daytime fatigue, mood changes, trouble concentrating
Cause of secondary hypertension
Obstructive sleep apnea
Fatigue, excessive thirst, peeing more than usual, headaches, muscle cramps or weakness, blurred vision
Cause of secondary hypertension
Primary aldosteronism
Confusion, trouble sleeping, edema, fatigue, headaches, loss of appetite, dry or itchy skin (these occur as the disease gets worse)
Cause of secondary hypertension
Renal artery stenosis

Your healthcare provider may suspect secondary hypertension if:

  • Your blood pressure is normally stable but suddenly goes up
  • You have high blood pressure before age 30
  • You develop dangerously high blood pressure (hypertensive crisis)
  • You’re taking at least three medicines to lower your blood pressure, but it’s still high (resistant hypertension)

Another red flag is high blood pressure that starts before puberty. If this happens to your child, their pediatrician may look for secondary causes.

What are the risks of secondary hypertension?

Untreated, secondary hypertension can lead to hypertensive heart disease. This is damage to your heart that results from years of high blood pressure. You may also develop complications from the condition that’s raising your blood pressure.

Secondary hypertension may be your provider’s first clue that you have another condition. Getting help for secondary hypertension may be the first step toward managing the underlying condition.

Diagnosis and Tests

How doctors diagnose this condition

Since there are many possible causes, it might take a while to reach a diagnosis. Your provider has to rule out some causes while investigating others in greater depth.

If your provider suspects you have secondary hypertension, they’ll start by:

  • Doing a physical exam
  • Reviewing your medical history, including any medications or supplements you’re taking
  • Talking with you about what you eat and drink, including things like sodium and alcohol
  • Doing some basic tests like an electrocardiogram (EKG/ECG), blood tests and urine tests

This information may help your provider find out why you have high blood pressure. If not, your provider will run further tests. The tests vary depending on the condition that your provider thinks you may have.

Management and Treatment

How is secondary hypertension treated?

Treatment depends on the cause. Since many different conditions can cause secondary hypertension, there are many possible treatments. Your healthcare provider will tailor a plan to your needs. They’ll explain what you can expect each step of the way.

As part of your plan, you may:

  • Take medications to lower your blood pressure
  • Take medications to treat other medical conditions
  • Change what you eat or drink
  • Limit alcohol
  • Quit smoking
  • Get regular physical activity
  • Use a device (like a CPAP machine)
  • Have a procedure or surgery

When should I see my healthcare provider?

See a provider for a yearly checkup. Your provider will check your blood pressure and let you know if it’s too high. Secondary hypertension itself doesn’t cause symptoms. So, you might not know your blood pressure is high — or that there’s a distinct reason why.

If you have high blood pressure, your provider will tell you how often to come in. They may also ask you to check your blood pressure at home. Follow their guidance and ask if you have any questions.

Outlook / Prognosis

What is the prognosis for secondary hypertension?

Secondary hypertension has a positive outlookwith treatment. Early detection and treatment can lower the risk of damage to your blood vessels and heart from ongoing high blood pressure.

This means it’s possible for secondary hypertension to go away. Your blood pressure may return to normal once you treat the underlying cause. But it’s also possible for your blood pressure to remain higher than it should be. This might be because there’s another cause. If this happens, you may need to take medicine to keep it in the healthy range.

A note from Wockr

Having secondary hypertension means there’s an identifiable cause behind your raised numbers. Often, that’s a medical condition that providers can diagnose and treat.

Learning the “why” behind your high blood pressure might feel like a relief. But you might also have many new questions as you figure out what the underlying condition means for you. Now’s the time to learn as much as you can about your diagnosis. Ask your provider how you can manage the condition to help lower your blood pressure. You’ll work together to develop a treatment plan that’s right for you.