Secondary hypertension can be caused by different factors and illnesses.

Among them there are:
A: ACCURACY, APNEA, ALDOSTERONISM

Accuracy. Sometimes the blood pressure is measured in a wrong way because a blood pressure cuff is of a small size and the blood pressure due to tight-fitting sleeves is high. White-coat hypertension is observed among 20 percent of people who have high blood pressure

Apnea. Hypertension is widespread among people who suffer from sleep apnea. Its treatment leads to the reduction of hypertension. 

B: BRUITS, BAD KIDNEYS
(RENAL PARENCHYAMAL DISEASE)

Bruits. Renovascular hypertension appears as a result of wrong arterial supply to the kidneys. It is common among people who are older than 50 and who have are prone to it (smokers, patients with diabetes, patients with known atherosclerotic disease). 65 percent of people suffer from renovascular hypertension.

People who suffer from renovascular hypertension have an abdominal which can be diagnosed in both systole and diastole hypertension. It can be diagnosed with the captopril (Capoten)-augmented radioisotopic renogram, Renal arteriography and with duplex ultrasound scanning.

Bad Kidneys. Renal parenchymal illness leads to hypertension. The renal damage makes the kidneys unable  to produce salt and excess fluid and it leads to the appearance of hypertension’s complications. Its treatment reduces blood pressute and helps to avoid renal complications.

C: CATECHOLAMINES, COARCTATION, CUSHING'S SYNDROME

Catecholamines. Excess catecholamine influence the appearance of white-coat hypertension and hypertension in pheochromocytoma, OSA... Stress leads to hypertension which is observed before and after the operation.
 
Coarctation of the Aorta. Coarctation of the aorta is a narrowing of the aortic lumen. It can lead to premature death.
Cushing's Syndrome. Cushing's syndrome leads to hypertension.