Pneumothorax (collapsed lung from accumulation of air between the lung and the chest wall) is a significant problem in patients with LAM. Up to 70% of patients will ultimately develop at least one pneumothorax in their lifetime and this is often the first sign of LAM. Most commonly, the pneumothorax occurs spontaneously without inciting factors (such as vigorous exertion). Unlike patients with Primary Spontaneous Pneumothorax (which occurs in patients without apparent underlying lung disease) who have about a 25% risk of recurrent pneumothorax after a first episode, three-quarters of women with LAM suffer from recurrence if nothing is done to prevent it. In a survey conducted from The LAM Foundation database, participants reported an average of 3.5 episodes of pneumothorax resulting in an average of one month total spent in the hospital.