When fluid builds up in the lungs, it can cause some distinct sounds that can be heard with a stethoscope. The extra fluid interferes with normal breathing and can make it more difficult for air to move in and out of the lungs. Some of the main lung sounds heard when excess fluid is present include:
Crackles
One of the most common abnormal lung sounds is crackles. These are discontinuous, explosive sounds that are often described as sounding like salt and pepper being sprinkled on a plate. Crackles are caused by fluid opening the small airways in the lungs as the person breathes. They can be heard most prominently when the person inhales.
Characteristics of crackles:
- Discontinuous, popping sounds
- Heard during inhalation
- Sound like salt and pepper being sprinkled
Wheezes
Wheezes are musical, whistling sounds that are caused by air moving through narrowed airways. The sound is often high-pitched and can sound similar to a whistling tea kettle. Wheezes occur during both inhalation and exhalation.
Characteristics of wheezes:
- High-pitched, musical, whistling sound
- Occur during inhalation and exhalation
- Sound like a whistling tea kettle
Rales
Rales describe crackling, bubbling sounds in the lungs. They are caused by fluid in the small bronchial tubes in the lungs. Rales can be heard during inhalation or exhalation and are often described as sounding like bubbles passing through water.
Characteristics of rales:
- Bubbling, crackling sounds
- Heard during inhalation or exhalation
- Sound like bubbles passing through water
Pleural rub
A pleural rub is the sound created by the inflamed pleural surfaces of the lungs rubbing together during breathing. It creates a coarse, scratching sound that is often described as feeling like sandpaper being rubbed together. Pleural rubs occur during inhalation and exhalation.
Characteristics of pleural rub:
- Coarse, scratchy, sandy sound
- Heard during inhalation and exhalation
- Feels like sandpaper being rubbed together
Stridor
Stridor refers to a high-pitched, musical sound heard during breathing. It is caused by a blockage or narrowing in the back of the throat or voice box (larynx). While not directly caused by fluid in the lungs, stridor can be a sign of swelling and fluid buildup compressing these upper airways.
Characteristics of stridor:
- High-pitched, musical wheezing
- Heard during inhalation
- Caused by narrowing of upper airway
When to See a Doctor
Abnormal lung sounds like crackles, wheezes, or stridor can be a sign of excess fluid buildup in the lungs. This is a serious medical condition that requires prompt evaluation by a doctor. Some reasons to see a doctor right away for lung sounds include:
- New crackles or wheezing that doesn’t go away
- Increasing shortness of breath or difficulty breathing
- Fever, chills, or coughing up sputum
- Chest pain that gets worse with breathing
A doctor can listen to the lung sounds with a stethoscope to help determine where fluid is accumulating. They may order imaging tests like a chest x-ray or CT scan to confirm the presence of fluid in the lungs (pulmonary edema). Prompt treatment is needed to help remove the excess fluid from the lungs and improve breathing.
Causes of Fluid Buildup in the Lungs
Some of the main causes of fluid accumulating in the lungs include:
Heart failure
When the heart is not pumping effectively, fluid can back up into the lungs causing pulmonary edema. This is the most common cause. Symptoms include shortness of breath, fatigue, and swelling.
Kidney disease
Damaged kidneys have trouble removing fluid from the body. This extra fluid can leak into the lungs.
Low protein levels
Proteins help keep fluid in the bloodstream. Low protein levels cause fluid to shift into the lungs.
Pneumonia
Lung infections cause inflammation that allows fluid leakage into the air sacs.
ARDS
Acute respiratory distress syndrome (ARDS) is a life-threatening lung injury that allows fluid buildup in the lungs.
Smoke inhalation
Inhaling smoke or chemical fumes damages the airways triggering fluid accumulation.
Risk Factors
Certain factors raise a person’s risk of developing pulmonary edema and excess fluid in the lungs:
- Congestive heart failure
- Coronary artery disease
- Hypertension
- Kidney disease
- Pneumonia
- Sepsis
- ARDS
- Smoking
Complications
Potential complications of fluid in the lungs include:
- Respiratory failure requiring oxygen therapy or mechanical ventilation
- Pneumonia
- Pulmonary hypertension
- Acute respiratory distress syndrome (ARDS)
- Collapsed lung (pneumothorax)
- Low blood oxygen levels
- Death in severe cases
Diagnosis
To diagnose fluid in the lungs, doctors use:
- Chest X-ray – Shows fluid in lungs as patchy, cloudy opacities.
- CT scan – Provides detailed images of excess fluid.
- Echocardiogram – Uses sound waves to evaluate heart function.
- BNP blood test – BNP levels are elevated with heart failure and fluid overload.
- Lung function tests – Measure airflow and lung capacity.
Treatment
Treatment options for fluid in the lungs involve:
- Treating the underlying cause – This may include medications for heart failure, kidney disease, or pneumonia.
- Oxygen therapy – Extra oxygen is given through a nasal cannula or face mask.
- Diuretics – These “water pills” help remove excess fluid through increased urination.
- Limiting salt and fluid intake – This reduces overall fluid accumulation.
- Medications – Blood pressure medications (ACE inhibitors, beta-blockers) can improve heart function and reduce fluid buildup.
- Pulmonary rehabilitation – Exercise training helps improve lung function.
- Surgery – This is rarely needed but may be an option to repair heart valves or implanted devices.
Most cases of fluid in the lungs can be effectively treated with diuretics, oxygen therapy, and treating the underlying medical issue. Severe, life-threatening pulmonary edema may require hospitalization in the intensive care unit for close monitoring and treatment.
Prevention
Ways to help prevent fluid accumulation in the lungs include:
- Controlling high blood pressure
- Properly managing heart failure with medications
- Quitting smoking
- Getting vaccines to prevent pneumonia
- Avoiding exposure to smoke, toxins, and chemicals
- Following a low-sodium diet
- Staying active and getting exercise
- Keeping other medical conditions like kidney disease well controlled
Outlook
The prognosis for fluid in the lungs depends on how quickly it is treated and the underlying cause. Acute pulmonary edema can be life-threatening and requires emergency medical care. With prompt treatment of mild cases, most people recover well. Recurrent pulmonary edema or chronic lung congestion has a poorer long-term outlook.
Following the treatment plan from your doctor and taking preventive measures can help prevent excess fluid from accumulating and obstructing normal breathing. Seek immediate medical care for symptoms like shortness of breath or crackling lung sounds to address the problem before it worsens.
Conclusion
Fluid in the lungs causes distinct adventitious lung sounds like crackles, wheezes, and rales. These abnormal sounds occur because the fluid interferes with normal air movement in the lungs’ airways. The sounds can be heard with a stethoscope during inhalation or exhalation. Prompt medical evaluation is necessary for abnormal lung sounds to identify the cause and prevent complications. With appropriate treatment, the outlook for pulmonary edema can be good, especially when caught early.