```html

Stridor – What It Is, Why It Happens, and When to Get Help

What is Stridor?

Stridor is a high‑pitched, noisy breathing sound that occurs when air flow is partially blocked in the upper airway (the larynx, trachea, or the large bronchi). The noise is usually heard during inhalation, but it can also be present on exhalation or both phases depending on the location and severity of the obstruction.

Unlike wheezing, which originates from the lower airways (bronchi and bronchioles), stridor points to a problem **above** the vocal cords. It may be soft and intermittent or loud and continuous, and its intensity can change with the person’s position, activity level, or illness progression.

Stridor can occur in anyone, but it is most commonly seen in infants and young children because their airways are smaller and more easily compromised. In adults, stridor often signals a more serious underlying condition and warrants prompt evaluation.

Common Causes

The following are the most frequent conditions that produce stridor. Some are pediatric‑specific, while others are seen across all age groups.

• Viral Croup (Laryngotracheobronchitis) – Inflammation of the larynx and trachea, usually caused by parainfluenza viruses.
• Epiglottitis – Bacterial infection (often Haemophilus influenzae type b) leading to rapid swelling of the epiglottis.
• Foreign Body Aspiration – Inhaled objects (e.g., nuts, coins) that lodge in the larynx or trachea.
• Bronchial or Subglottic Stenosis – Narrowing of the airway from congenital malformations, prolonged intubation, or scarring.
• Laryngeal Tumors – Benign or malignant growths that encroach on the airway lumen.
• Allergic Angioedema – Rapid swelling of the tongue, lips, or larynx after an allergic reaction.
• Respiratory Syncytial Virus (RSV) Infection – Particularly in infants, RSV can cause severe airway inflammation.
• Tracheal Compression – From enlarged thyroid, mediastinal masses, or vascular anomalies.
• Vocal Cord Paralysis – Neurologic injury or surgical trauma that prevents the vocal cords from opening adequately.
• Acute Laryngitis – Inflammation from over‑use (shouting), gastroesophageal reflux, or infection.

Associated Symptoms

Stridor rarely occurs in isolation. The following signs often accompany the noisy breathing and can help clinicians narrow the cause.

• Hoarseness or loss of voice
• Fever, chills, or malaise (suggesting infection)
• Difficulty swallowing or drooling (especially with epiglottitis)
• Cough that is bark‑like (classic for croup) or harsh and persistent
• Chest retractions or “pleading” (use of extra muscles to breathe)
• Rapid breathing (tachypnea) or low oxygen saturation
• Chest or neck pain
• Vomiting or a sensation of something “stuck” in the throat
• Swelling of the face, lips, or tongue (angioedema)
• Fainting or altered mental status (late sign of severe hypoxia)

When to See a Doctor

Because stridor can indicate a life‑threatening airway obstruction, you should seek medical attention promptly if any of the following occur:

• The stridor is **new, loud, or worsening** over a short period.
• You notice **difficulty breathing**, rapid breathing, or use of accessory muscles (retractions, neck muscles pulling in).
• There is **high fever** (> 38.5 °C / 101.3 °F) or signs of systemic infection.
• Swelling of the tongue, lips, or face develops, especially after an insect bite, medication, or food exposure.
• Fever, drooling, or a “hands‑in‑the‑air” position (child holding the neck and mouth open) suggests epiglottitis.
• Persistent coughing, choking, or a history of aspirating a foreign object.
• Any stridor in an adult combined with **chest pain, hoarseness, or a recent upper‑airway surgery**.

In infants less than 3 months old, even mild‑appearing stridor warrants evaluation because their airways are tiny and can decompensate quickly.

Diagnosis

Healthcare providers use a step‑wise approach that combines history, physical examination, and targeted tests.

History and Physical Exam

• Onset, duration, triggers (e.g., cold air, allergens, recent illness).
• Exposure to potential foreign bodies or recent surgeries.
• Vaccination status (croup and epiglottitis incidence have dropped with widespread vaccination).
• Inspection of airway patency, listening for inspiratory vs. expiratory stridor.
• Evaluation of neck and chest for retractions, tenderness, or masses.

Imaging

• Neck X‑ray (AP & lateral) – Can reveal a “steeple sign” (subglottic narrowing) in croup or a thumbprint sign in epiglottitis.
• Chest X‑ray – Helps rule out lower‑airway disease and can show a foreign body.
• CT or MRI of the neck – Used when tumors, vascular compressions, or complex congenital anomalies are suspected.

Endoscopic Evaluation

Flexible or rigid laryngoscopy performed by an otolaryngologist (ENT) allows direct visualization of the airway and can confirm inflammation, foreign bodies, or structural lesions.

Laboratory Tests

• Complete blood count (CBC) – looks for infection or eosinophilia (allergic causes).
• Blood cultures if sepsis is a concern.
• Viral panels (e.g., RSV, influenza) in children during respiratory season.

Treatment Options

Treatment is directed at the underlying cause and at maintaining a patent airway. Below is a practical guide for both medical professionals and caregivers.

Medical Interventions

• Corticosteroids (e.g., dexamethasone 0.15–0.6 mg/kg PO/IV) – First‑line for croup, reduces airway edema.
• Nebulized Epinephrine – Provides rapid, temporary relief for moderate‑to‑severe croup or epiglottitis.
• Antibiotics – Indicated for bacterial epiglottitis (IV ceftriaxone or cefotaxime) or for secondary bacterial infection.
• Antihistamines & Corticosteroids – For allergic angioedema (e.g., diphenhydramine + oral prednisone).
• Bronchoscopy – To retrieve a foreign body or assess severe stenosis.
• Surgical Airway – Tracheostomy or cricothyrotomy in cases where the airway cannot be secured by less invasive means.

Home Care & Supportive Measures

• Keep the child upright; gravity can reduce airway edema.
• Humidified air (cool‑mist humidifier or sitting in a steamy bathroom) may soothe mild croup.
• Encourage fluids to prevent dehydration, especially if fever is present.
• Monitor temperature and breathing every 2–4 hours; report worsening stridor promptly.
• For adults with chronic airway narrowing (e.g., post‑intubation stenosis), follow prescribed inhaled steroids or anti‑inflammatory therapy.

Prevention Tips

While some causes (congenital anomalies, tumors) cannot be prevented, many common triggers are modifiable.

• Vaccinate children against Haemophilus influenzae type b, pertussis, influenza, and COVID‑19 to lower the risk of epiglottitis and severe viral croup.
• Practice safe feeding habits for infants (avoid small, hard foods that can be aspirated).
• Supervise toddlers during play to prevent accidental inhalation of small objects.
• Manage allergies proactively with antihistamines or immunotherapy to reduce angioedema risk.
• Avoid exposure to tobacco smoke and indoor pollutants that irritate the airway.
• Maintain good oral hygiene and prompt treatment of upper‑respiratory infections to reduce secondary bacterial complications.
• For patients with known airway stenosis, follow scheduled ENT follow‑ups and adhere to prescribed dilatation or steroid regimens.

Emergency Warning Signs

Key Take‑aways

Stridor signals a narrowing of the upper airway and can range from a mild, self‑limiting sound in viral croup to a rapidly fatal obstruction in epiglottitis or foreign‑body aspiration. Prompt recognition, appropriate medical assessment, and early treatment are essential, especially in infants and young children. If you ever doubt the severity, err on the side of caution and seek emergency care.

---

References:

1. Mayo Clinic. “Stridor.” https://www.mayoclinic.org. Accessed May 2026.
2. American Academy of Pediatrics. “Croup (Laryngotracheobronchitis).” https://www.healthychildren.org. 2023.
3. Cleveland Clinic. “Epiglottitis.” https://my.clevelandclinic.org. 2024.
4. National Institute of Allergy and Infectious Diseases. “Respiratory Syncytial Virus (RSV) Infection.” https://www.niaid.nih.gov. 2022.
5. World Health Organization. “Guidelines for the Management of Acute Respiratory Infections.” WHO Press, 2023.

```