The pleura are two thin, moist membranes around the lungs. The inner layer is attached to the lungs. The outer layer is attached to the ribs. Pleural effusion is the buildup of excess fluid in the space between the pleura. The fluid prevents the lungs from fully expanding. This causes shortness of breath. Symptoms are more likely when a pleural effusion is moderate or large-sized, or if inflammation is present.Symptoms of pleural effusions may include:1. Wheezing2. Hiccups3. Excessive fatigue4. Chest pain5. Chest pain that worsens while coughing6. Chest pain that worsens with breathing7. Pain is usually sharp8. Back pain9. Shoulder pain10. Rapid breathing rate11. Cough12. Breathing difficulty:13. Shortness of breath with exertion14. Waking up short of breath15. Shortness of breath when lying flat