The outcome of pneumothorax depends upon the extent and type of pneumothorax.
A small spontaneous pneumothorax will generally resolve on its own without treatment.
A secondary pneumothorax (even when small) associated with underlying disease is much more serious and has a significant death rate. A secondary pneumothorax requires urgent and immediate treatment.
Having one pneumothorax increases the risk of developing the condition again. Most recurrences occur within the first year.