What are the causes of extreme pain?
<answer> The causes of Severe joint pain mentioned in various sources: 1 Avascular necrosis 2 Bartonella infections 
3 Bartonellosis 4 Hemoglobin S/hemoglobin Lepore, Boston 
5 Hemoglobin S/hemoglobin O. <context> The list below shows some of the causes of Severe joint pain mentioned in various sources: 1  Avascular necrosis - severe joint pain. 2  Bartonella infections - severe joint pain. 3  Bartonellosis - severe joint pain. 4  Hemoglobin S/hemoglobin Lepore, Boston - severe joint pain. 5  Hemoglobin S/hemoglobin O, Arab - severe joint pain.