Hypertension or high blood pressure is one of the major risk factors for cardiovascular complications. There are three types of hypertension based on its causative factors — primary, secondary and white coat hypertension. Multiple factors like obesity, genetics, age, a high sodium diet and a sedentary lifestyle can cause primary hypertension. Having high blood pressure in the presence of a doctor or at a medical facility is often classified as white coat hypertension which is also considered as an early warning for the impending onset of primary hypertension. Blood pressure fluctuations could also be caused due to existing or new medical conditions and infections in your body which is classified as secondary hypertension.
Dr. Divya Marina Fernandes, heart failure specialist and interventional cardiologist at Aster RV Hospital in Bengaluru explains that secondary hypertension occurs because of an underlying condition. This sets it apart from primary hypertension, which is often linked to family history and age.
Experts add that one should suspect secondary hypertension when their blood pressure is not under control even with adequate medications and lifestyle modification, or if there is a sudden rise in blood pressure in children.
Causes of secondary hypertension
The causes of secondary hypertension include:
1. Renal parenchymal diseases
Renal parenchymal can be caused by diseases or disorders that affect the kidneys directly or indirectly. According to Dr Fernandes, these diseases include chronic glomerulonephritis (Glomerulonephritis is a kidney disease that damages the glomeruli — tiny filters inside the kidney). People with this condition may develop hypertension from an early stage, diabetic nephropathy (kidney disease that occurs in people with diabetes), polycystic kidney disease (a genetic disorder that causes fluid-filled cysts to grow in the kidneys) and glomerulosclerosis (scarring of the glomeruli in the kidneys).
“Renal disorders should be well managed with antihypertensive medications and prevent progression to chronic kidney disease,” adds Dr Fernandes.
Dr Vanita Arora, senior consultant cardiac electrophysiologist and interventional cardiologist at Apollo Hospital Delhi says that the narrowing of the arteries that supply blood to the kidneys or renal artery stenosis can also increase blood pressure and is also listed as a reason for secondary hypertension.
2. Endocrine disorders
Dr Arora adds that conditions like Cushing’s syndrome (over-production of the stress hormone cortisol by the adrenal glands or from long-term use of steroid drugs), primary aldosteronism (an endocrine condition that occurs when the adrenal glands produce too much of the hormone aldosterone) and pheochromocytoma (neuroendocrine tumor) can lead to secondary hypertension.
3. Thyroid disorders
Experts explain that both hyperthyroidism (the thyroid gland does not produce enough hormone) and hypothyroidism (the thyroid gland produces excess thyroid hormone) can cause hypertension as they affect the thyroid gland’s production of hormones.
4. Coarctation (narrowing) of the aorta
Coarctation of the aorta is a congenital heart defect that narrows the aorta, the body’s largest artery. This could also lead to hypertension. The narrow aorta blocks normal blood flow to the body causing a rise in blood pressure. “Coarctation of aorta can be corrected by either surgery or through balloon angioplasty and stenting,” says Dr Fernandes.
5. Preeclampsia in pregnancy
According to experts, preeclampsia is a chronic hypertensive condition that arises during pregnancy. It is characterized by high blood pressure and signs of liver or kidney damage.
6. Obstructive sleep apnea (OSA)
OSA is a sleep disorder that prevents an individual from normal breathing during sleep by causing a partial or complete block of airways. “OSA can also increase the risk of developing secondary hypertension as they keep mean blood pressure levels elevated at night or even during the day for some people,” adds Dr Fernandes.
7. Polycystic ovarian syndrome (PCOS)
It is a common endocrine disorder in women and is a risk factor for hypertension. Experts add that if left uncontrolled, high blood pressure can damage blood vessels and organs.
8. Drugs
“Various drugs including painkillers (non-steroidal anti-inflammatory drugs), herbal supplements and recreational drugs can increase the risk of hypertension,” adds Dr Fernandes. Recreational drugs can also increase blood pressure and the risk of cardiovascular complications.
Experts add that it is important to diagnose the causes of secondary hypertension so one can prevent any cardiovascular complications of the underlying condition.
Managing secondary hypertension
According to Dr Fernandes, management of secondary hypertension includes adequate blood pressure control with antihypertensive medications, lifestyle modification and most importantly treating the underlying cause.
“Regular exercise (at least 30 minutes for 5 days a week), fiber-rich diet, no smoking and consumption of alcohol, adequate sleep and reduced stress are important ways to manage and prevent it from further worsening. Getting regular health checks earlier is recommended especially if there is a strong family history of hypertension, diabetes, kidney or heart disease,” says Dr Arora.
