---
title: "Stridor VS Stertor"
description: "Key differences between Stridor and Stertor."
source: "The ENT Resident"
author: "Dr. Mausumi Das"
canonical_url: "https://www.theentresident.com/ent-notes-lectures/stridor-vs-stertor-differences"
categories: ["Larynx and Trachea", "Differences Tables in ENT"]
video: "https://www.youtube.com/watch?v=xiviu0EeOSM"
image: "https://media.theentresident.com/og-images/stridor-vs-stertor-differences.png"
---

# Stridor VS Stertor

Key differences between Stridor and Stertor. Watch the full video lecture on YouTube: https://www.youtube.com/watch?v=xiviu0EeOSM

## Stridor vs Stertor - Differences

Stridor and Stertor are both forms of **noisy breathing**, but they differ significantly in their **site of obstruction, mechanism, clinical significance, and associated features**.


| Feature | Stridor | Stertor |
| --- | --- | --- |
| **Definition** | Harsh, high pitched musical sound due to turbulent airflow through a narrowed airway | Low pitched snoring like sound due to upper airway obstruction |
| **Nature of Sound** | Musical, squeaky | Snoring, rumbling, gurgling |
| **Pitch** | High pitched | Low pitched |
| **Mechanism** | Turbulent airflow through partially obstructed laryngeal or tracheal airway | Vibration of soft tissues in nasopharynx or oropharynx |
| **Primary Site of Obstruction** | Supraglottis, glottis, subglottis, trachea | Nasopharynx or oropharynx |
| **Respiratory Phase** | May be inspiratory, biphasic, or expiratory depending on site of obstruction | Predominantly inspiratory |
| **Effect of Crying** | Worsens on crying and exertion | Usually unchanged |
| **Effect of Position** | Usually unaffected by position | Worse in supine position |
| **Associated Cough** | Usually present | Usually absent |
| **Voice Changes** | Hoarseness if glottis involved | Usually normal |
| **Cry** | May become hoarse if glottic pathology present | Muffled cry |
| **Severity** | Often indicates potentially life threatening airway obstruction | Usually less urgent unless severe airway compromise occurs |
| **Typical Age Group** | Common in infants and children but can occur at any age | Occurs at all ages; OSA more common in adults |
| **Audibility** | Audible even without a stethoscope | Commonly heard during sleep or relaxation |
| **Site of Best Audibility** | Neck or tracheal region | Nose or mouth |
| **Urgency** | Airway emergency until proven otherwise | Usually less acute |
| **Underlying Pathology** | Laryngeal or tracheal narrowing | Pharyngeal airway obstruction |

---

### Common Causes of Stridor

* Croup
* Epiglottitis
* Laryngomalacia
* Tracheomalacia
* Subglottic stenosis
* Airway foreign body
* Laryngeal edema
* Vocal cord paralysis

---

### Common Causes of Stertor

* Obstructive sleep apnea
* Adenoid hypertrophy
* Tonsillar hypertrophy
* Choanal atresia
* Macroglossia
* Nasopharyngeal obstruction
* Oropharyngeal obstruction

---

### Viva Pearls

* **Stridor = Laryngeal or Tracheal obstruction**
* **Stertor = Nasopharyngeal or Oropharyngeal obstruction**
* Stridor is generally considered an **airway emergency**
* Stertor is classically described as a **snoring type noisy breathing**
* Site of best audibility helps differentiate the two:

  * Neck → Stridor
  * Nose/Mouth → Stertor

> What does Inspiratory stridor indicate?

> What does Expiratory stridor indicate?

> What does Biphasic stridor indicate?

> What are the different types of cough seen in different types of Stridor?

---

## About This Note

This free ENT note on Stridor VS Stertor was written by Dr. Mausumi Das and is paired with a corresponding video lecture.

Canonical page of this note: https://www.theentresident.com/ent-notes-lectures/stridor-vs-stertor-differences

When citing or referencing this content, please credit The ENT Resident and link to the canonical page above.

## Related Notes by Category

- Larynx and Trachea: https://www.theentresident.com/ent-notes-lectures/category/larynx-and-trachea.md
- Differences Tables in ENT: https://www.theentresident.com/ent-notes-lectures/category/differences-tables-in-ent.md

## About The ENT Resident

The ENT Resident is an educational website and resource library created by Dr. Mausumi Das (MS ENT) for ENT residents, ENT postgraduates preparing for exams, and MBBS students.

Dr. Mausumi Das writes the notes, draws the diagrams, and records the lectures herself.

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