<P> While there are limited clinical α - blocker uses, in which most α - blockers are used for hypertension or benign prostatic hyperplasia, α - blockers can be used to treat a few other diseases, such as Raynaud's disease, congestive heart failure (CHF), pheochromocytoma, and erectile dysfunction . </P> <P> Furthermore, α - blockers can occasionally be used to treat anxiety and panic disorders, such as posttraumatic stress disorder (PTSD) induced nightmares . Studies have also had great medical interest in testing alpha blockers, specifically α blockers, to treat Type II diabetes and psychiatric depression . </P> <P> Hypertension is due to an increase in vascular resistance and vasoconstriction . Using α selective antagonists, such as prazosin, has been efficacious in treating mild to moderate hypertension . This is because they can decrease vascular resistance and decrease pressure . However, while these drugs are generally well tolerated, they have the potential to produce side effects such as orthostatic hypotension and dizziness . </P> <P> Another treatment for hypertension is using drugs that have both α blocking activity, as well as nonselective β activity, such as Labetalol or carvedilol . In low doses, labetalol and carvedilol can decrease the peripheral resistance and block the effects of isoprenaline to reduce hypertensive symptoms . </P>

What is a alpha blocker and how does it work