Adventitious breath sounds, like crackles, in the lungs usually indicate cardiac or pulmonary conditions. This HealthHearty article describes the types of crackles and the conditions which can cause crackling in the lungs.
The additional sounds that are heard over normal breath sounds are called abnormal or adventitious breath sounds. They are described as crackles (rales), wheezes (rhonchi), pleural friction rubs, and stridor.
The lungs play an important role in breathing. So, lungs are primarily responsible for the breathing sounds. Normal or abnormal breathing sounds originate in large airways, as air velocity and turbulence create vibrations in the airway walls. The lung tissue and the thoracic wall transmit these vibrations to the surface. Doctors can hear these sounds clearly with the help of a stethoscope.
Crackles are also known as rales. They can be described as small clicking, bubbling, or rattling sounds in the lungs. Such popping sounds are heard when air is forced through the respiratory passages that are narrowed or closed by fluid, mucus, or pus. They can be heard on intake or release of air.
If a person is suffering from a respiratory disease, either one of his lungs or both his lungs can make crackling noises while breathing (inhaling and exhaling air). When such noises come out of both the lungs, they are referred to as bilateral crackles. When the crackles originate in or near the base of a lung, they are known as basilar or basal crackles (basal rales). The crackles which originate at the bases of both the lungs, are known as bibasilar or bibasal crackles, or bilateral basilar crackles (basal crackles in both the lungs).
What Causes Crackles In the Lungs
Acute or Chronic Bronchitis
Swelling and inflammation in the passages that carry air to the lungs is called acute bronchitis. It results in increased secretion of mucus. The person experiences difficulty in breathing, as swelling narrows the airways. Cough is the most common symptom of acute bronchitis. On the other hand, chronic bronchitis occurs when there is an injury to the epithelium of the bronchi leading to chronic swelling. Chronic bronchitis effects can be mild or severe, but they last for months or years. The bronchial tubes continue to be swollen, irritated, and produce excessive mucus over time. Smoking is the most common cause of this condition, and one has to stop smoking to overcome or get rid of it.
As you know, our body releases certain chemicals to fight an infection. Sepsis occurs when these chemicals trigger inflammatory responses throughout the body. A severe bacterial infection can cause sepsis. However, a fungal, viral, or parasitic infection can also cause sepsis. Whole-body inflammation can trigger a cascade of changes that can damage multiple organ systems, causing them to fail. Poor lung function can lead to difficulty in breathing.
Permanent enlargement of certain parts of the airways in the lungs is described as bronchiectasis. It is a type of obstructive lung disease. Conditions such as pneumonia, tuberculosis, and cystic fibrosis, etc., can lead to bronchiectasis. Due to an excessive inflammatory response, the function of the airways gets severely affected. The affected bronchi cannot clear secretions. This leads to increased amount of bacteria in the lungs, and airway blockage. Eventually, the condition results in further breakdown of the airways.
This type of lung infection can occur in both the lungs due to bacteria or viruses. It often occurs after an attack of cold and flu. One can cough, have fever, and may find it difficult to breathe. In case of bacterial pneumonia, a child usually becomes sick very quickly, and experiences a sudden onset of high fever and rapid breathing. When pneumonia is caused by viruses, symptoms tend to appear more slowly, and are often less severe as compared to those of bacterial pneumonia. One may experience chest pain while coughing and breathing.
Cancer is a disease of uncontrolled cell growth in body tissues, and the same is in case of lung cancer. The disease can affect lung function seriously.
Congestive Heart Failure (CHF)
Congestive heart failure occurs when the heart is not able to pump sufficient blood, and the needs of the organs are not met due to insufficient blood flow. This can lead to dyspnea (breathlessness), fatigue, and leg swelling. Coronary artery disease, high blood pressure, and cardiomyopathy, etc., can lead to CHF.
It involves scarring of lung tissues. The lungs cannot function properly as the tissues are thickened and stiffened. The most common symptoms are dry cough, fatigue, pain in muscles and joints, and difficulty in breathing.
Excess fluid in the lungs is referred to as pulmonary edema. Usually, heart problems like CHF, pneumonia, exposure to certain toxins, trauma to the chest wall, etc., lead to this condition.
Severe medical conditions can lead to lung collapse or atelectasis. Reduced or no gas exchange due to deflated alveoli (small hollow cavities or air sacs in the lungs) is referred to as atelectasis.
One may experience crackles in the lungs after a surgery, especially after a thoracic surgery.
Types of Crackles
Crackles in the lungs can be described as moist, dry, fine, and course.
Properties of Fine Crackles
- The sound is soft and high pitched.
- It is very brief.
Properties of Coarse Crackles
- The sound is loud and low in pitch.
- It is long-lasting (lasts longer than fine crackles).
With the help of an X-ray, the doctor can examine the lungs. Taking into consideration the symptoms exhibited by the patient, the doctor would find out the reason behind the noise produced. The treatment would depend upon the cause. Generally, the main cause behind crackling is pneumonia.
As mentioned above, an infection that leads to the inflammation of small bronchi, bronchioles, and alveoli can cause crackles in the lungs. The adventitious breath sound that doesn’t clear after a cough suggests pulmonary edema or fluid in the alveoli due to heart failure or adult respiratory distress syndrome (ARDS).
Due to sedentary lifestyle, bad habits like smoking, unhealthy diet, and exposure to harmful chemicals (pollution), the possibilities of lung diseases like emphysema (a type of chronic obstructive pulmonary disease, COPD, involving damage to the air sacs in the lungs), followed by symptoms like crackles in the lungs are endangering our daily lives.
Disclaimer: This HealthHearty article is for informative purposes only, and should not be replaced for the advice of a physician/nutritionist.