Most cases of angioedema are mast cell mediated. We present three patients with angioedema, who were admitted to our emergency room or outpatient clinic. One of them did have mast cell mediated angioedema, despite insufficient response to initial antihistamine treatment. The other patients had more rare cases of angioedema, i.e. hereditary angioedema with C1-inhibitor deficiency and angiotensin converting enzyme inhibitor associated angioedema. We discuss similarities and differences in symptoms, diagnosis and treatment between these causes of angioedema. We recommend keeping the differential diagnosis of angioedema in mind when a patient with angioedema is presented, including rarer pathophysiological explanations.