Hello Thank you for trusting HCM What about Systolic blood pressure??? /100 What you have inherited erythema?? Or arrhythmias?? Diastolic pressure is the force exerted by the blood on the walls of arteries as it flows through these blood vessels between heartbeats. Causes of isolated diastolic blood pressure 1.primary IDH: IDH caused by primary hypertension, the underlying reason for the arteriolar narrowing is poorly understood. Unusually high levels of certain substances that raise blood pressure, such as angiotensin, or inappropriate contraction of tiny muscles in the arteriole walls are two possible reasons. Genetic factors may also contribute. 2 . endocrine causes : An underactive thyroid, or hypothyroidism, is one of the more common secondary causes of IDH. As in primary hypertension, the elevated diastolic pressure is the result of excessive arteriolar narrowing. Causes elevation of diastolic blood pressure. If not corrected thyroid problem blood pressure not respond to the medicine. 3 . renal problems : Most diseases that damage the kidney can lead to IDH by reducing the ability of the kidneys to remove fluids from the body or by increasing the production of angiotensin. Renovascular hypertension, due to narrowing of the main artery leading to the kidneys, is another possible cause of IDH.if not correct the renal problem difficult 4 . obstructive sleep apnea :IDH due to excessive arteriolar narrowing and decreased fluid excretion by kidney. Chronic excessive alcohol consumption can also lead to IDH. If patients who have high diastolic blood pressure but normal Systolic blood pressure Careful while taking clonidine this drug cause rebound hypertension if you stop abruptly. Please consult your doctor for further assistance.