★ Crackles or Rales: These are characterized by crackling or rattling noises occurring towards the end of inhalation. They are typically observed in patients with “moist” or congested lungs, such as those with pulmonary edema or pneumonia. These sounds are usually more distinct when listening at the lower lung bases.
★ Wheezing: Wheezing presents as high-pitched, whistling sounds during exhalation. It is commonly heard in patients with asthma, particularly when their airways become constricted during an asthmatic episode. Wheezing tends to be louder during exhalation and continuous in nature.
★ Stridor: Stridor manifests as harsh, high-pitched sounds during inhalation. It occurs in the upper airway of patients with significant narrowing or obstruction. Stridor can often be heard without the need for a stethoscope and usually signals a potentially life-threatening issue with the airway.
★ Rhonchi: Rhonchi are coarse, gravelly sounds resembling wheezing but originating from sources other than the alveoli. They are caused by thick secretions in the airways and are typically more pronounced during exhalation.
