What is a side effect of heparin?

A. Bleeding: Heparin enhances the activity of antithrombin III, which inhibits clotting factors and prolongs clotting time. This mechanism increases the risk for bleeding, making it the most common and clinically significant adverse effect requiring close monitoring. B. Hyperglycemia: Heparin does not interfere with insulin secretion or glucose metabolism. Elevated blood glucose levels are more commonly associated with corticosteroids, stress responses, or uncontrolled diabetes rather than anticoagulant therapy. C. Constipation: Heparin does not affect gastrointestinal motility. Constipation is more frequently linked to opioid analgesics, anticholinergic medications, or reduced fluid and fiber intake. D. Thrombus: Heparin is used to prevent and treat thrombus formation by inhibiting coagulation pathways. While heparin-induced thrombocytopenia can paradoxically increase clot risk, thrombus formation is not a typical direct side effect.