Upper respiratory infections

Respiratory disorders, a prevalent health concern globally, are generally divided into two primary categories: upper and lower respiratory tract disorders. The categorization is based on the area of the respiratory system they affect.
Upper respiratory disorders impact the airways above the vocal cords, encompassing areas like the nose, sinuses, and throat. Various conditions fall under this category, including the common cold and allergic rhinitis. These disorders can stem from several causes,...

The human respiratory tract, comprising the upper and lower segments, serves as a critical interface with the external environment. The upper respiratory tract (URT)—including the nostrils, sinuses, pharynx, and oropharynx—is heavily colonized by microbes, while the lower respiratory tract (LRT), composed of the larynx, trachea, bronchi, and lungs, was long thought to be sterile. However, recent molecular studies have revealed that the lungs are not devoid of microbes but act more like...

Upper respiratory tract disorders, including viral infections and allergic rhinitis, cause significant discomfort and disrupt daily life. Managing these conditions involves a variety of drugs, such as antihistamines, intranasal steroids, decongestants, antitussives, expectorants, and mucolytics. Specific examples of drugs in each category are provided.
Antihistamines (e.g., Benadryl) block histamines from binding. Histamines are chemicals released during an allergic reaction in the body. As a...

Influenza is an acute, highly communicable viral disease that affects the respiratory tract and is responsible for seasonal epidemics worldwide. Influenza A is the most prevalent type associated with widespread outbreaks and is subtyped based on two surface glycoproteins: hemagglutinin (H) and neuraminidase (N), as in H1N1. These glycoproteins are essential for viral infectivity, transmission, and immune recognition. Transmission occurs primarily through respiratory droplets and contaminated...

The upper respiratory tract plays a vital role in the respiratory system, comprising several structures that facilitate air intake and prepare air for the lungs. It also serves as the first line of defense against pathogens and particles. This tract includes the nose and nasal cavity, the oral cavity, the paranasal sinuses, and the pharynx, each with specific functions and features.
Nose and nasal cavity
The nose and nasal cavity represent the main external openings of the respiratory tract.

Introduction
Acute pharyngitis is the inflammation of the back of the throat (pharynx), commonly resulting in a sore throat. It is a frequently encountered condition that prompts individuals to seek medical advice.
Classification
Acute pharyngitis can be categorized based on its underlying cause: