A bilateral injury causes the vocal folds to impair the air flow resulting in breathing problems, stridor and snoring sounds, and fast physical exhaustion.

[4] The most commonly reported symptom patients with either vocal fold paresis or paralysis make is having a rough voice quality.

[4][6] Symptoms of sensory nerve damage include: chronic coughing, the feeling of having a lump in the throat (globus sensation), hypersensitivity or abnormal sensation, spasms of the vocal folds (laryngospasms), dysphagia, pain from vocal use, and voice loss in high pitch ranges.

[3] If maladaptive compensatory strategies are used more and more to try to offset the voice difficulties, the vocal mechanisms will fatigue and the above symptoms will worsen.

[3] In the absence of imaging, either invasive (e.g. laryngoscopy) or non-invasive (e.g. computed tomography scan), congenital VFP can be detected in infants through the presence of stridor (i.e. a high-pitched wheezing resulting from a blockage in the larynx or trachea), difficulties feeding, an abnormal sounding cry or excessive hoarseness.

Although it was originally identified in patients with left atrial enlargement,[14] the definition has expanded to include aneurysms of the aortic arch,[15] pulmonary hypertension due to mixed connective tissue disease,[16] or aberrant subclavian artery[17] syndrome among other causes of left recurrent laryngeal nerve palsy with cardiovascular origin.

The GRBAS is used to rate the patient's voice quality on 5 dimensions: grade (overall severity), roughness, breathiness, asthenia (weakness) and strain.

The CAPE-V is used in a similar manner, rating of the dimensions of voice quality on a subjective scale from 0–100, and using this to determine an overall severity score.

[citation needed] In the presence of neural lesions with unknown cause, a thorough ENT endoscopy[19] with additional imaging techniques (computed tomography (CT) of the chest, particularly in the case of left-sided paralyses, and magnetic resonance imaging (MRI) of the neck including the base of the skull and the brain, ultrasound examination of the neck) are performed to exclude tumors along the laryngeal nerves.

When tumor formation is suspected, parts of the hypopharynx and the upper esophagus and passive mobility of the arytenoid cartilage are endoscopically examined under anesthesia.

Breathing tests (spirometry, body plethysmography) are used to measure impairment of respiratory flow through the larynx, particularly in patients with bilateral paralysis.

The treating physician must view all examination results combined[5] and establish an individual diagnosis and treatment plan for each patient.

[4][3] It is a condition with a variable profile, as the severity of the paresis can range on a wide continuum from minor to major loss of vocal fold mobility.

[4] Due to its variable nature, the progression of vocal fold paresis may fluctuate, so it may be characterized differently from one evaluation to the next.

In the absence of any additional pathology, the first step of clinical management should be observation to determine whether spontaneous nerve recovery will occur.

[23] Voice therapy with a speech-language pathologist is suitable at this time, to help manage compensatory vocal behaviours which may manifest in response to the paralysis.

[24] Lip and tongue trills aid in the balance of resonance, as well as coordinate the muscles of respiration, phonation and articulation.

In addition, subglottal pressure may increase during lip trills, and result in the generation greater vocal fold vibration.

[24] After 9 months of observation, should the paralysis not resolve and the patient be dissatisfied with the outcomes of voice therapy, the next option is temporary injection medialization.

[25] In this procedure, a variety of materials can be injected into the body of the vocal fold in order to bring it closer to the midline of the glottis.

[25] Materials such as Teflon, autologous fat, collagens acellular dermis, fascia, hydroxyapatite and hyaluronates are available to be used in the procedure.

[26] The choice of substance is dependent on several factors, taking into consideration the specific condition and preference of the patient as well as the clinical practice of the surgeon.

[25] This surgical procedure introduces a shim between the inner wall of the larynx and the soft tissue supporting the vocal fold.

[28] As a result, the paralyzed vocal fold is supported in a position closer to the midline of the glottis, and retains its ability to vibrate and phonate efficiently.

[26] This medical procedure consists of pulling the vocal processes of the arytenoid medially while monitoring the voicing quality being produced by the patient.

[24] Due to the complex and controversial nature of this condition,[3] epidemiological (incidence) reports vary significantly and more research in this area is needed.

Instead of reporting the incidence of this condition within the general population, most studies are conducted within specialized voice disorder clinics.