How does cabin pressurization affect aircraft fuselage structural design?

Cabin pressurization creates hoop stress (tension around the circumference) and longitudinal stress in the fuselage skin, with hoop stress typically twice the longitudinal stress. The pressure differential (typically 8-9 psi for cruise at 40,000 ft) creates significant fatigue loading through each flight cycle (pressurization and depressurization). Fuselage design must account for: sufficient skin thickness for pressure loads, crack stopping features to prevent rapid depressurization, inspection access to critical areas, and door/window frame reinforcement where stress concentrations occur.