Work-related stress — increasing due to the current economic crisis — can lead to illness and cost businesses millions of euros in reduced productivity, says an Italian study. The Centre for Adaptive Disorders and Headache at the University of Pavia in Italy suggests that loss of productivity due to headaches alone can have a significant economic impact. Researchers suggest that firms should introduce initiatives to relieve stress in the workplace. The study suggests that 4 to 5% of the global population suffers from chronic daily headache.