HYPERTENSION: CAUSES OF SECONDARY HYPERTENSION
White Coat Hypertension – Increase in BP due to being in a GP surgery (nervous).
Isolated Systolic Hypertension – increase in systolic pressure but have a normal diastolic
pressure.
Primary Hypertension – Most people – no specific known cause (range of things).
Secondary Hypertension – increase in BP due to other pathology. (less than 2% of cases).
If BP increases, results in chronically high afterload leading to Left ventricle hypertrophy
(thickening of the LV). Also get coronary atherosclerosis due to high BP rupturing blood
vessels.
Atherosclerosis can also lead to ischaemia or infarction.
CAUSES OF SECONDARY HYPERTENSION
1. Renal Artery Stenosis
Narrowing in renal artery due to either atherosclerosis in elderly men or
build up of fibronectin in young women; therefore, kidney only sees the BP
as being low.
Therefore, RAAS system is activated and increases the blood volume and
hypertension occurs.
2. CoArctation of Aorta
Narrowing of the aorta so key thing to look for is that BP is usually higher in
arms than legs as the narrowing is usually after the subclavian artey.
See notched appearance on ribs in X-ray due to dilation of aorta.
3. Conn’s Syndrome
Adrenal tumour secreting aldosterone – over activation of RAAS system;
therefore, high BP.
4. Cushing’s Syndrome
Excess glucocorticoids
Look like a cushion.
Pituitary tumour – produces ACTH – pushes adrenals to produce cortisol and
increase BP.
5. Phaeochromocytoma
Rare, catecholamine secreting tumour.
Prepare body for physical activity; therefore, increase HR and BP.
6. Pre-eclamptic toxaemia
Placental ischaemia leads to release of agents causing endothelial
dysfunction; therefore, reduced NO levels.
Increased vasoconstriction and natriuresis.
Therefore, increased H2O and blood volume.
7. Hyperthyroidism
Increased secretion of thyroid hormones; therefore, increase in cardiac
output and volume.
White Coat Hypertension – Increase in BP due to being in a GP surgery (nervous).
Isolated Systolic Hypertension – increase in systolic pressure but have a normal diastolic
pressure.
Primary Hypertension – Most people – no specific known cause (range of things).
Secondary Hypertension – increase in BP due to other pathology. (less than 2% of cases).
If BP increases, results in chronically high afterload leading to Left ventricle hypertrophy
(thickening of the LV). Also get coronary atherosclerosis due to high BP rupturing blood
vessels.
Atherosclerosis can also lead to ischaemia or infarction.
CAUSES OF SECONDARY HYPERTENSION
1. Renal Artery Stenosis
Narrowing in renal artery due to either atherosclerosis in elderly men or
build up of fibronectin in young women; therefore, kidney only sees the BP
as being low.
Therefore, RAAS system is activated and increases the blood volume and
hypertension occurs.
2. CoArctation of Aorta
Narrowing of the aorta so key thing to look for is that BP is usually higher in
arms than legs as the narrowing is usually after the subclavian artey.
See notched appearance on ribs in X-ray due to dilation of aorta.
3. Conn’s Syndrome
Adrenal tumour secreting aldosterone – over activation of RAAS system;
therefore, high BP.
4. Cushing’s Syndrome
Excess glucocorticoids
Look like a cushion.
Pituitary tumour – produces ACTH – pushes adrenals to produce cortisol and
increase BP.
5. Phaeochromocytoma
Rare, catecholamine secreting tumour.
Prepare body for physical activity; therefore, increase HR and BP.
6. Pre-eclamptic toxaemia
Placental ischaemia leads to release of agents causing endothelial
dysfunction; therefore, reduced NO levels.
Increased vasoconstriction and natriuresis.
Therefore, increased H2O and blood volume.
7. Hyperthyroidism
Increased secretion of thyroid hormones; therefore, increase in cardiac
output and volume.
