What is the Difference Between Primary Hypertension and Secondary Hypertension?
The difference between primary hypertension and secondary hypertension is the causes related to each. Primary hypertension does not have a definitive cause, while secondary hypertension has a known cause. Both primary and secondary hypertension result in high blood pressure.
Hypertension is often labeled the "silent killer" because people often have no symptoms of high blood pressure until something significant occurs, such as a heart attack or stroke.
Continue reading to learn more about the distinction between primary hypertension and secondary hypertension, as well as their symptoms, causes, and risk factors.
What is Primary Hypertension?
Primary hypertension is high blood pressure that is most likely caused by environmental and genetic factors. Primary hypertension is also called essential hypertension and is associated with a number of risk factors that are strongly and independently associated with it.
Risk factors for primary hypertension include:
Age (risk increases with advancing age)
Obesity
Family history
Race
Diet (high salt diet)
Alcohol consumption (>8 drinks/week)
Physical inactivity
Primary hypertension accounts for 90-95% of adult cases, and according to the World Health Organization, of those cases, about 60% of people are not receiving the treatment they need.
What is Secondary Hypertension?
Secondary hypertension is high blood pressure that is caused by other medical conditions. In many cases, secondary hypertension may coexist with risk factors associated with primary hypertension. Major causes of secondary hypertension include prescription medications, over the counter medications, and underlying disease processes.
The following are major causes of secondary hypertension:
Oral contraceptives (particularly those with higher levels of estrogen)
NSAIDs (chronic use of nonsteroidal anti-inflammatory agents)
Antidepressants (tricyclics, SSRI, and MAOIs)
Corticosteroids
Decongestants
Stimulants (methylphenidate, amphetamine)
Atypical Antipsychotics
Angiogenesis inhibitors
Kidney disease
Endocrine disorders (hypothyroidism, hyperthyroidism, Cushing's syndrome)
According to the National Institute of Health, secondary hypertension accounts for 2-10% of adult cases.
Primary Hypertension vs Secondary Hypertension
Primary and Secondary hypertension both result in high blood pressure but have different causes.
Primary Hypertension (essential hypertension) | Secondary hypertension (resistant hypertension | |
|---|---|---|
90-95% of adults with hypertension | X | |
2-10% of adults with hypertension | X | |
Underlying and potentially correctable causes | X (diet is potentially correctable, e.g. high salt diet) | X |
Usually kidney or hormonal disorder | X | |
Develops gradually over many years | X | |
Develops suddenly | X | |
Related to age, race, family history, diet, and inactivity/obesity | X |
People with elevated blood pressure are more likely to develop hypertension and other heart-related complications. It is important to know when you are at risk for health problems. The American Heart Association defines elevated blood pressure as 120 to 129 over less than 80. Blood pressure is categorized as normal, elevated, stage 1, stage 2, and crisis.
Blood Pressure | Systolic (upper number) | And/or | Diastolic (lower number) |
|---|---|---|---|
Normal | Less than 120 | And | Less than 80 |
Elevated | 120-129 | And | Less than 80 |
HBP stage 1 | 130-139 | Or | 80-89 |
HBP stage 2 | 140 or higher | Or | 90 or higher |
Hypertensive Crisis (emergency) | Higher than 180 | And/or | Higher than 120 |
Related: How to Get an Accurate Blood Pressure Reading at Home
Primary Hypertension Causes
Although the exact cause of primary hypertension remains unclear, several risk factors have been identified and correlated with increased risk of developing heart disease and other diseases.
The risk factors of primary hypertension include:
Age
Obesity
Family history
Race
High salt diet
High alcohol consumption (8-15 drinks per week)
Inactivity
Smoking
Things to consider about primary hypertension causes include:
The older you become, the more at risk you are of developing high blood pressure. In the United States, high blood pressure affects 76% of adults aged 65-74 and 82% for adults aged 75 years and older.
Hypertension is a common problem among those who are overweight and do not exercise consistently and who are inactive during the day.
If you have a relative who also has high blood pressure, your risk is increased.
Studies have also shown that Black people appear more likely to develop primary hypertension in comparison to other races.
Diets high in salt and alcohol consumption greatly increase the risk of developing hypertension.
Read More: How to Understand Blood Pressure Ranges by Age
Primary Hypertension Symptoms
Early signs and symptoms of primary hypertension are usually silent or undetectable, which is why it is termed the "silent killer." Later signs and symptoms of primary hypertension include fatigue, dizziness, lightheadedness, headaches, nosebleeds, blurry vision, and chest pain. When you experience these symptoms, it is more than likely you have had a gradual increase in blood pressure over time, that went undetected. Scheduling a virtual doctor visit to assess these symptoms becomes essential for timely evaluation and care.
Secondary Hypertension Causes
Secondary hypertension is caused by another medical condition that can be easily explained. Secondary hypertension is also referred to as resistant hypertension. Major causes of secondary hypertension include kidney disease, aldosteronism, and sleep apnea. Less common causes of secondary hypertension include oral contraceptives, Cushing's syndrome, hyperparathyroidism, and chemotherapy.
Risk factors of secondary hypertension include suboptimal blood pressure management, lifestyle and diet, prescription medications, and underlying medical conditions such as kidney disease.
Secondary Hypertension Symptoms
Symptoms give clues to the type of hypertension you have. Secondary hypertension symptoms usually come on abruptly, are severe and resistant, and are associated with endocrine disorders, electrolyte imbalances, or prescription medications.
Secondary hypertension symptoms may include:
Severe or resistant hypertension (high blood pressure despite medication management)
An acute, sudden rise in blood pressure
Low potassium in blood work
High levels of creatinine in blood work
Symptoms that are signs of a serious type of blood pressure that need to be treated as soon as possible include:
Severe headache
Chest pain
Severe pain in your upper back
Problems breathing
Nausea or vomiting
Vision changes
Blood in your urine
Confusion
Problems speaking
Weakness on one side of your body
Related: Why Lab Tests Are Important When Taking Hypertension Medication
Talk to a Doctor About Hypertension
Hypertension is a common illness, often requires prescription medications, and is the most common reason for office visits. Many people are unaware they have high blood pressure and many people diagnosed do not have adequate blood pressure control. If you have high blood pressure or a family history of high blood pressure, book an appointment and consult with our certified online doctors at PlushCare about risk factors and treatment plans.
Read More About Primary Hypertension
Sources
Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Hypertension. 2018 Jun;71(6):e13-e115. Epub 2017 Nov 13. Erratum in: Hypertension. 2018 Jun;71(6):e140-e144. Accessed on March 1, 2022 at https://pubmed.ncbi.nlm.nih.gov/29133356/
World Health Organization.(2021). Joint News Release. More than 700 million people with untreated hypertension. Accessed on March 1, 2022 at https://www.who.int/news/item/25-08-2021-more-than-700-million-people-with-untreated-hypertension
US National Library of Medicine National Institute of Health (2016). Secondary hypertension in adults. Singapore medical journal, 57(5), 228–232. Accessed on March 1, 2022 at http://www.smj.org.sg/article/secondary-hypertension-adults
