May be none! Or:
- Sudden onset dyspnoea,
- Pleuritic chest pain,
- Respiratory distress.
- On affected side:
- ↓Chest Expansion
- Reduced breath sounds
- Deviated trachea especially in tension (away from the affected side).
- shock and distended neck veins (for tension in particular.)
If tension pneumothorax is suspected, don't do any, you'll be wasting time - this is a life threatening emergency.
Otherwise, use chest X-ray to determine the extent and progression of the pneumothorax - one covering 15% or less of the hemithorax can be managed conservatively by observation but should be monitored to ensure it doesn't expand. It is visible by an area of blackness without normal lung markings, and the presence of the white line for visceral pleura away from the chest wall.
If tension pneumothorax, insert wide-bore needle into 2IC mid-clavicular line. This converts it to a simple pneumothorax (and even if they had no sort of pneumothorax before, because you have pierced the pleural space they certainly have one now!).
Large simple pneumothoraxes are treated by placing a chest drain with a water seal.