High blood pressure is developed very often unknowingly. High blood pressure causes are wide range of reasons that are possible to control. Some reasons are unavoidable but if we take early care, can reduce the impact of high blood pressure in our body.
As according to CDC, in 2019 only in United States, high blood pressure was a primary or contributing cause of death for 516,955 people. So high blood pressure is a silent killer of the body. That is why high blood pressure causes are very important to know.
As high blood pressure is basically classified into two basic types (primary and secondary hypertension), so the high blood pressure causes also differs based on the types of hypertension.
Primary High Blood Pressure Causes (Primary Hypertension)
Primary hypertension or essential hypertension is a type of hypertension where an identifiable cause of hypertension can not be determined. The causes of primary hypertension are the following
- Familial or genetic – Primary hypertension runs in the families generation after generation. A familial history of hypertension is seen.
- No identifiable cause– No identifiable single reversible cause is seen in this type of hypertension. Simply means, there is no detectable cause, the removal of which can lead to decrease of high blood pressure. In most patients with primary hypertension, some behaviors are seen such as excessive consumption of salt, calories, or alcohol – all these lead to elevated blood pressure.
Secondary High Blood Pressure Causes (Secondary Hypertension)
High blood pressure or hypertension can develop due to various reasons. There are several known causes of high blood pressure. The below mentioned causes lead to secondary hypertension. Secondary hypertension is also known as identifiable hypertension. In this type of hypertension, high blood pressure causes can be identified.
High blood pressure can be due to more than one causes mentioned below. In a person with hypertension, more than one cause can be seen. So, proper diagnosis of the type of hypertension and proper evaluation of the high blood pressure causes are a vital part to control the high blood pressure.
Depending upon the cause of hypertension, the treatment of hypertension varies.
- Parenchymal diseases
- Renal cysts (including polycystic kidney disease)
- Renal tumors (including renin secreting tumor)
- Obstructive uropathy
Any disease of kidney can cause hypertension. Kidney disease is the most common cause of secondary hypertension.
Hypertension is present in more than 80% of patients with renal failure. So, whatever the renal disease is, if hypertension develops, treatment should be started early to control the blood pressure and to decrease the progression of kidney disease.
- Fibromuscular dysplasia
Renovascular hypertension is a potentially curable cause of hypertension. In this condition, hypertension develops due to occlusion of renal artery.
Older arteriosclerotic patients who have renal artery obstruction due to the plaque and patients with fibromuscular dysplacia are at more risk to develop renovascular hypertension.
- Primary aldosteronism – In this condition, there is excess aldosterone production, so the hypertension develops. It is potentially a curable form of hypertension if treatment is given.
- Cushing’s syndrome – In this condition, there is excess cortisol production, as a result hypertension develops. Hypertension occurs in 75-80% of patients with Cushing’s syndrome.
- 17α-hydroxylase deficiency
- 11β-hydroxylase deficiency
- 11-hydroxysteroid dehydrogenase deficiency (licorice)
- Pheochromocytoma – This a condition due to catecholamine secreting tumors. In this condition there is increased circulating catecholamines that causes hypertension.
Coarctation of the aorta is the most common congenital cardiovascular cause of hypertension. Even if the surgical correction of anatomic lesion is done in infancy, up to 30% of patients develop subsequent hypertension and there is risk to develop coronary artery disease.
Obstructive Sleep Apnea
Hypertension occurs in more than 50% of patients with obstructive sleep apnea. If the sleep apnea is more severe, then the hypertension is also more severe and vice versa. It is important to note that, approximately 70% of patients with obstructive sleep apnea are obese.
When patient has drug resistant hypertension and a history of snoring, then obstructive sleep apnea also should be considered as one of the possible reason of high blood pressure causes.
Preeclamsia or eclampsia can cause hypertension. So, in the diagnosis of high blood pressure, eclampsia or preeclampsia should be considered as one of the possible reason of high blood pressure causes.
Neurogenic (Nerve Related) Cause
- Diencephalic syndrome
- Familial dysautonomia
- Polyneuritis (acute porphyria, lead
- Acute increased intracranial pressure
- Acute spinal cord section
Neurogenic or nerve related causes can result in hypertension or high blood pressure. Depending upon the high blood pressure causes, the treatment should be given to control the high blood pressure.
Miscellaneous Hormonal Causes
- Hypothyroidism or underactive thyroid – In this condition, mild diastolic hypertension can be seen.
- Hyperthyroidism or overactive thyroid- In this condition, systolic hypertension is most commonly seen.
- Hypercalcemia – Hypercalcemia due to any reason can cause hypertension. The most common cause of hypercalcemia that cause hypertension is primary hyperparathyroidism.
- Acromegaly – This condition is also due to a hormonal disorder that causes hypertension.
Hormonal imbalance is one of the potential reason of high blood pressure causes. In the evaluation of high blood pressure causes, hormonal disorder must be considered.
Medications that is different types of drugs, both prescription drugs and over the counter drugs can cause hypertension. A person with high blood pressure should avoid the below mentioned drugs. If needed, then the below mentioned drugs should be taken with caution.
- High-dose estrogens
- Adrenal steroids
- Appetite suppressants
- Tricyclic antidepressants
- Monoamine oxidase inhibitors
- Nonsteroidal anti-inflammatory agents
Medicines are one of the possible reason of high blood pressure. So, medicines is one factor of high blood pressure causes. In the evaluation of high blood pressure, history of medicine is very important. You should mention to your doctors about all the medicines you take. As medicine is a potential factor of high blood pressure causes, so thorough medicine history is a vital part in high blood pressure treatment.
Hypertension Other Causes
Obesity and The Metabolic Syndrome
Obesity and the metabolic syndrome is associated with hypertension. Various study reports suggest that there is well documented association of hypertension with obesity. It is the reason that obesity is an important factor of high blood pressure causes.
Obesity (body mass index greater than 30 kg/m2) leads to a higher risk to develop high blood pressure. In fact, more obese or more body weight a person has, chances to develop high blood pressure increases accordingly and vice versa.
Study also indicates that 60% with hypertension adults are more than 20% overweight.
Also, centrally located body fat (such as increased abdominal or belly fat) causes more elevation of blood pressure than peripheral located fat (fat in the arms, legs, etc.).
It is seen that change of body weight leads to change of blood pressure over time. That is why control of weight is an important part of high blood pressure treatment.
People with metabolic syndrome has insulin hormone resistance, hypertension, abdominal obesity, dyslipidemia.
So, obesity and metabolic syndrome is an important cause that leads to hypertension.
Dietary Sodium Intake
Dietary sodium intake is an important behavioral factor that can lead to hypertension, especially when there is genetic association to develop high blood pressure.
Sodium is an important element in our body, but excessive and uncontrolled consumption of sodium can cause hypertension in susceptible person. Mutations of salt handling genes are many times responsible for development of hypertension in these persons.