Hypertension is a disease influenced by multiple factors. Stenosis of blood vessels can certainly cause hypertension, especially when there is a narrowing of the abdominal aorta, renal arteries or aortitis, which can cause secondary hypertension. In addition, more often than not, it is the result of a combination of factors. For example, genetics, age, lack of physical activity, high salt diet, heavy alcohol consumption, elevated homocysteine, or chronic stress and anxiety. Most of the time, it is difficult to distinguish the exact cause of hypertension with the current medical technology, and it is customary to refer to hypertension caused by a combination of these factors as “hypertension” or “primary hypertension”. In a small percentage of people with hypertension, the exact cause of the hypertension can be identified, and this type of hypertension is called “secondary hypertension”. Common causes of secondary hypertension include chronic renal insufficiency, hyper- or hypothyroidism, aortic or renal artery stenosis, aortitis, pheochromocytoma, and aldosteronism. Appropriate tests are needed to clarify. Generally speaking, those who are young and have particularly high or fluctuating blood pressure are more likely to have secondary hypertension, and a detailed examination in a specialist is necessary before treatment.