Can doxazosin cause dizziness and shortness of breath?

Sure can: Doxazosin can lower your blood pressure significantly causing dizziness and shortness of breath. This can happen even after you've been on it a long time, though it's more common when you first start it. Side effects are not common, but they definitely can occur.

Yes: More common dizziness or lightheadedness less common blurred vision confusion dizziness, faintness, or lightheadedness when getting up from a lying or sitting position fainting (sudden) fast and pounding heartbeat irregular heartbeat shortness of breath sweating swelling of feet or lower legs.