Abstract: A thermochemical ablation system can be used to ablate a portion of a bodily structure, such as a human airway. In some examples, the thermochemical ablation system includes a first ablation reagent, a second ablation reagent, and an expandable balloon positioned adjacent the distal end of a catheter. The expandable balloon can be inserted into the bodily structure and the two ablation reagents combined to cause an exothermic reaction that generates heat. The heat may create a substantially uniform temperature distribution across the surface of the expandable balloon, providing substantially uniform ablation of tissue adjacent the balloon.