What is an upper respiratory infection?

An upper respiratory infection (URI) is typically referred to as the common cold. More than 200 different viruses can cause URIs. You can pick one up anywhere. They tend to strike seasonally during the late fall and winter months.
The sheer number of cold viruses makes it next to impossible for you to develop immunity against them.
Symptoms of an upper respiratory infection
The classic symptoms of an upper respiratory infection are:
- Stuffy and runny nose
- Sore throat
- Fever
- Sneezing
- Cough
- Headache
- Reduced appetite
Children are especially vulnerable to the common cold. URIs spread through person-to-person contact, especially touching. Sneezing or coughing in public can also spread the virus.
Handling objects that someone with a URI has been in contact with may also infect you. Frequent hand washing is the best way to protect yourself from common cold infections.
Home remedies for an upper respiratory infection
Upper respiratory infections have no cure. Antibiotics have no effect on them. Antibiotics will help stop a bacterial infection. They will not treat your URI, which is a viral infection.
Treatment for an upper respiratory infection is usually just a matter of easing your symptoms. Get plenty of rest, drink lots of fluids, and simply wait it out.
Some home remedies to help the cold pass through your body a little faster are:
Saline nasal sprays
Saline nasal sprays are safe for everyone, including children. They can be purchased at your pharmacy and may relieve your stuffy nose symptoms.
Do not confuse saline nasal sprays with nasal decongestant sprays. These can actually make your URI worse.
Humidifiers
Humidifiers also work well for stuffy nose symptoms produced by URIs. A cool mist humidifier in your bedroom can normalize your breathing.
Talk to your doctor before you use one. Excessive humidity in the air can actually worsen allergies in some people.
Over-the-counter (OTC) medicines
Many people regularly take OTC medicines like acetaminophen during cold and flu season.
Be careful. A side effect of acetaminophen is that it can cause liver damage if overused. Do not give acetaminophen to a child under the age of 6 unless your doctor advises it.
Fasting
Your child will probably avoid eating when they have an upper respiratory infection. This might cause you some understandable anxiety, but you shouldn’t worry.
Doctors typically advise against forcing your child to eat when they have a URI. Let them eat when they’re hungry and reintroduce solid food gradually.
Fluids
You or your child may be more inclined to drink than eat when you have a cold. This is a healthy impulse. Don’t ignore it.
Consider popsicles, warm soups, and broth in addition to increasing your water intake. All of these can be comforting when you have an upper respiratory infection.
Honey
Honey is highly recommended as a remedy for coughs and some other symptoms associated with URIs. Both children and adults benefit from mixing honey with boiling water to treat their acute coughs.
Do not give honey to an infant under the age of 1. Your baby should not consume honey at all.

QUESTION
Which illness is known as a viral upper respiratory tract infection? See AnswerWhen to see a doctor for an upper respiratory infection
The viruses that cause upper respiratory infections usually run their course within 10 days. Schedule an appointment with your doctor if your URI lasts longer than this. Persistent symptoms might indicate that something more serious is behind them.
Symptoms like chills, fever, and coughing up phlegm are common to upper respiratory infections. Call your doctor if these last longer than 10 days.
There are also a few severe symptoms to watch out for during a cold, including:
- Painful breathing
- Shortness of breath
- Wheezing
- Chest tightness
- A fever of over 101 degrees Fahrenheit that lasts longer than two days.
If you notice any of these, at any stage of the illness, call your doctor.
Prognosis and outlook for an upper respiratory infection
Don’t be at all surprised if the symptoms of your upper respiratory infection get worse during the first three to five days. This is normal. You should see gradual improvement after that period. With or without treatment, most URIs run their course in less than two weeks.
What does the respiratory system do?
The primary function of the respiratory system is to help you breathe, supplying your body with oxygen and expelling carbon dioxide.
Learn more about what your respiratory system does, what organs are involved, and what disease can affect its ability to do its job.
8 functions of the respiratory system
- Gas exchange: During this process, air moves in and out of the lungs, continuously refreshing gases in the air sacs. Oxygen enters the body and is carried to the cells of the body, where it is exchanged for carbon dioxide and expelled via the lungs. This process is essential to maintain oxygen saturation in body tissues.
- Maintaining body pH: Cells are active hubs of biochemical reactions that sustain life, and these cells require a specific pH to work. The lungs and the respiratory system maintain pH levels by regulating bicarbonate and hydrogen ion levels.
- Sense of smell and taste: The nasal passages and the olfactory system help the body perceive smell. Because taste and smell are interlinked, the respiratory system helps the body perceive taste as well.
- Immune function: The respiratory system has immunoglobulin A type of antibodies (surface antibodies) and an inherent local immune system, which plays a role in immunity and sensitization. The respiratory immune response is made up of multiple types of cellular responses (both innate and acquired) that are engaged in a sequential manner to control infections. The respiratory tract protects the body from pathogen invasion. Airway epithelial cells secrete antibodies, enzymes, peptides, and small oxidative molecules that inhibit pathogenic colonization. Furthermore, some of the epithelial cells secrete mucus to trap larger dust particles. The respiratory system contains specialized lymphoid tissue capable of producing lymphocytes as a first-line defense. Coughing and sneezing are also important mechanisms to fight infections because they remove large amounts of bacteria or viruses trapped in mucus.
- Drug metabolism: Drugs such as inhaled anesthetics and asthma medications are often metabolized in the lungs and then expelled from the body.
- Blood pressure control: Angiotensin-converting enzyme (ACE) plays a central role in generating angiotensin II from angiotensin I, which has a role in blood pressure control. The lungs as well as the capillary blood vessels are some of the major sites of ACE expression and angiotensin II production in the body.
- Production of sounds: An intact upper respiratory system (pharynx and trachea) is needed to produce sounds. This permits speaking, coughing, sneezing, and swallowing.
- Surfactant production: Lung epithelial cells produce surfactant, which aids in the process of inhalation and exhalation. Adequate surfactant production by fetal lung cells is a critical requirement for viability in preterm births.
What are the parts of the respiratory system?
The respiratory system is divided into two sections.
- Upper respiratory tract
- Lower respiratory tract
Upper respiratory tract
- Mouth and nose: Air enters the body through the mouth and nose. Mucus secretions and hairs in the nose warm, moisten, and filter the air.
- Larynx or voice box: The larynx is located at the very top of the trachea and has vocal cords. When breathing in, air travels through the larynx, trachea, and lungs. When exhaling, air travels from the lungs up the trachea and out the nose and mouth. The vocal cords tighten and move closer together when speaking. Air from the lungs causes the vocal cords to vibrate, generating sound.
- Trachea: The trachea is the tube that connects the mouth, nose, and lungs.
Lower respiratory tract
- Bronchial tubes: In the lungs, the trachea divides into two bronchial tubes. These are the left and right bronchus. The bronchial tubes continue to branch off into smaller and smaller tubes called bronchi. Cilia, which are fine hair-like structures, line the tubes. Mucus is carried upward by the cilia as they sway back and forth to the trachea, where it can be coughed up or swallowed.
- Alveoli: Alveoli are air sacs located at the ends of the bronchial tubes, resembling grape bunches. This is the point at which oxygen enters the blood and carbon dioxide exits. Each lung contains approximately 300 million alveoli.
- Lungs: The lungs are composed of pink, spongy lobes, three to the right and two on the left. The heart is located between them, slightly to the left.
- Diaphragm: The diaphragm is a long, flat muscle located beneath the lungs. By moving up and down, it helps get air in and out of the lungs. The diaphragm moves down when breathing in and up when breading out.
What are common diseases of the respiratory system?
Diseases of the respiratory tract can develop as a result of:
- Obstruction in the airway
- Constriction of the passages
- Loss of the large surface area of the alveoli for gas exchange
- Problems with the capillaries that surround the alveoli, which could be either from clots or altered cardiac function.
Long-term conditions or short-term infections include:
Common cold
- The common cold is caused by a variety of viruses, with rhinoviruses being the most diverse and common cause of this complaint.
- It is typically an upper respiratory tract infection, but it can occasionally spread to the ears or lower respiratory structures as well.
- The infection is spread through direct contact with an infected person, particularly through nasal discharges.
- This is especially difficult to prevent because a person is infected before they show symptoms.
- Viruses typically contact nose cells, which then produce a clear liquid to trap and expel these microorganisms from the body.
- This is followed by sneezing and coughing, particularly if the virus has spread further into the airway.
- Coughing up thick, yellow or green sputum indicates that these microbes are being attacked by the host's immune system.
- Antibiotics are ineffective against viral infections, and symptoms usually resolve within a week.
- Tuberculosis (TB) is at the other end of the spectrum of infectious diseases of the respiratory tract.
- It is a bacterial infection caused by Mycobacterium tuberculosis that, prior to the development of powerful antibiotics, could often result in death.
- The infection spreads through the transmission of live bacteria from infected people, particularly through oral and nasal discharge.
- Because the bacterium is hardy and can survive in a desiccated state for many months, the illness can quickly spread to epidemic proportions in areas with high population density or during a prolonged cold season in which people stay indoors and interact closely with one another.
- Many healthy children and adults can recover from infections without showing any symptoms, and only a blood test can confirm that an infection has occurred.
- Immunocompromised people, such as infants, the elderly, or those suffering from autoimmune diseases, are more vulnerable to the recurrence of this illness.
- Treatment usually entails taking multiple antibiotics over a long period.
- Lung cancer is the development of a malignant tumor in the lungs, which is associated with uncontrolled cell growth within the tissues and metastasis to other organs within the body.
- Smoking, especially when started at a young age, is the most significant risk factor of lung cancer.
- Though tobacco smoking is responsible for more than 80% of lung cancer cases, any chemical that repeatedly irritates the delicate inner linings of the lung can result in the formation of a tumor. Asbestos, chromium, nickel, radon gas, uranium dust, and coal dust are examples.
- The bone is the most common site of lung cancer metastasis. As a result, advanced stages of the disease include bone pain.
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How does COVID-19 affect the respiratory system?
One of the most serious ways that COVID-19 affects the respiratory system is by attacking the lungs, where the virus reaches a dangerous level and mimics sinus infection symptoms.
There are a few serious respiratory diseases that can be caused directly by the virus:
- Pneumonia: Pneumonia caused by COVID-19 has very serious symptoms, causing long-term effects. Breathing difficulties may persist for months after pneumonia has resolved, frequently mimicking asthma and symptoms of a sinus infection.
- Acute respiratory distress syndrome (ARDS): ARDS is a type of lung failure characterized by shortness of breath that can occur as a result of severe pneumonia. Those who have the disease and watch it progress this far may develop permanent pulmonary scarring.
- Sepsis: Sepsis is a serious complication that occurs when the infection spreads to the bloodstream and causes long-term damage to the body's tissues. Like ARDS, it can cause long-term damage to organs, particularly the lungs.
- Multiple organ dysfunction syndrome (MODS): Septic shock can trigger an unprecedented immune response that causes damage to the kidneys, liver, brain cells, and other organs.
In each case, the resulting damage may be severe and last longer than the disease that caused it. It is critical to understand each of these complications so that if a person starts to experience symptoms, they can notify their doctor immediately.
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Children's Hospitals and Clinics of Minnesota: "Upper Respiratory Infections (Colds)."
Cornell Health: "Caring for an Upper Respiratory Infection (URI)."
Johns Hopkins Medicine: "Upper Respiratory Infection (URI or Common Cold)."
Nationwide Children's: "Upper Respiratory Infections (Colds)."
National Health Service: "Honey, not antibiotics, recommended for coughs."
Piedmont Healthcare: "When to see a doctor for a cold."
University of Wisconsin Eau Claire Student Health Service: "Upper Respiratory Infection."
Image Source: iStock Images
University of Rochester Medical Center: "Anatomy of the Respiratory System."
Butte College: "Structure and Function of the Respiratory System [Internet]."
University of Cincinnati: "The Respiratory System."
Arteriosclerosis, Thrombosis, and Vascular Biology: "COVID-19 and Respiratory System Disorders: Current Knowledge, Future Clinical and Translational Research Questions."
Healthline: "Respiratory."
Medical News Today: "How Does the Respiratory System Work?"
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