Pulmonary hypertension is high blood pressure in the lung vessels.
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Commonly this occurs due to back pressure from heart disease, but pressure can also rise because of lung disease, previous clots in the lungs (pulmonary embolism), or from thickening and spasms of the very small lung vessels.
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Pulmonary arterial hypertension (small vessel disease) is a rare condition that causes breathlessness anduntreated leads to heart failure. Fortunately many therapies (pulmonary vasodilators) have been developed over the past two decades, though there is further work to do.
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Pulmonary arterial hypertension is common in patients with scleroderma and may have an autoimmune and/or genetic basis.