Upper Respiratory Infection (URI)

The upper respiratory tract includes the sinuses, nasal passages, pharynx, and larynx. These structures direct the air we breathe from the outside to the trachea and eventually to the lungs for respiration to take place.

An upper respiratory tract infection, or upper respiratory infection, is an infectious process of any of the components of the upper airway.

Infection of the specific areas of the upper respiratory tract can be named specifically. Examples of these may include:

• Rhinitis (inflammation of the nasal cavity)
• Sinus infections, which include sinusitis or rhinosinusitis (inflammation of the sinuses located around the nose)
• Nasopharyngitis, or common cold (inflammation of the nares, pharynx, hypopharynx, uvula and tonsils)
• Pharyngitis (inflammation of the pharynx, uvula and tonsils)
• Epiglottitis (inflammation of the upper portion of the larynx or epiglottis)
• Laryngitis (inflammation of the larynx)
• Laryngotracheitis (inflammation of the larynx and trachea)
• Tracheitis (inflammation of the trachea)

Upper respiratory infections are one of the most frequent causes for a doctor visit, with symptoms ranging from a runny nose, sore throat and cough to breathing difficulty and lethargy. In the United States, upper respiratory infections are the most common illness leading to missing school or work.

Although upper respiratory infections can happen at any time, they are most common in the fall and winter months, from September to March. This may be explained because these are the usual school months when children and adolescents spend a lot of time in groups and inside closed doors. Furthermore, many viruses of upper respiratory infection thrive in the low humidity of winter.

Is an upper respiratory infection contagious?

A majority of upper respiratory infections are due to self-limited viral infections. Occasionally, bacterial infections may cause upper respiratory infections. Most often, upper respiratory infections are contagious and can spread from person to person by inhaling respiratory droplets from coughing or sneezing. The transmission of respiratory infections can also occur by touching the nose or mouth by hand or other objects exposed to the virus.

Upper respiratory infections are generally caused by the direct invasion of the inner lining (mucosa or mucus membrane) of the upper airway by the culprit virus or bacteria. For pathogens (viruses and bacteria) to invade the mucus membrane of the upper airways, they have to fight through several physical and immunologic barriers.

The hair in the lining of the nose acts as a physical barrier and can potentially trap the invading organisms. Additionally, the wet mucus inside the nasal cavity can engulf the viruses and bacteria that enter the upper airways. There are also small hair-like structures (cilia) lining the trachea, which constantly move any foreign invaders up towards the pharynx to be eventually swallowed into the digestive tract and the stomach.

In addition to these intense physical barriers in the upper respiratory tract, the immune system also does its part to fight the invasion of pathogens or microbes entering the upper airway. Adenoids and tonsils, located in the upper respiratory tract, are a part of the immune system and help fight infections. Through the actions of the specialized cells, antibodies and chemicals within these lymph nodes, invading microbes are engulfed within them and are eventually destroyed.

Despite these defense processes, invading viruses and bacteria adopt various mechanisms to resist destruction. They can sometimes produce toxins to impair the body's defense system or change their shape or outer structural proteins to disguise from being recognized by the immune system (change of antigenicity). Some bacteria may produce adhesion factors that allow them to stick to the mucus membrane and hinder their destruction.

It is also important to note that different pathogens have varying abilities to overcome the body's defense system and cause infections.

Furthermore, different organisms require varying times of onset — from when they enter the body to when symptoms occur (incubation time). Some of the common pathogens for upper respiratory infection and their respective incubation times are as follows:

The table shows the incubation period of the common pathogens for an upper respiratory infection.

Some common risk factors for upper respiratory infection are:

• Physical or close contact with someone with an upper respiratory infection
• Poor handwashing after contact with an individual having an upper respiratory infection
• Close contact with children in a group setting, schools or day care centers
• Contact with groups of individuals in a closed setting, such as traveling, tours and cruises
• Smoking or secondhand smoking (may impair mucosal resistance and destroy the cilia)
• Health care facilities, hospitals nursing homes
• Immunocompromised state (compromised immune system) such as HIV, organ transplant, congenital immune defects, long-term steroid use
• Anatomical abnormalities such as in facial trauma, upper airway trauma and nasal polyps

Upper respiratory vs. lower respiratory infection

Upper respiratory infections (URIs) and lower respiratory infections (LRIs) are both caused by viruses or bacteria that enter the respiratory system. URIs affect the upper part of the respiratory system, including the sinuses and throat, while LRIs affect the airways and lungs.

The table below summarizes the differences between URIs and LRIs.

Recognizing these differences is crucial for proper diagnosis and effective treatment. If you are experiencing respiratory symptoms, consult a health care professional to determine the root cause and receive appropriate medical care.

Generally, upper respiratory infection symptoms result from the toxins released by the pathogens as well as the inflammatory response mounted by the immune system to fight the infection.

Common URI symptoms generally include:

• Nasal congestion
• Rhinorrhea (runny nose)
• Nasal discharge (may change from clear to white to green)
• Nasal breathing
• Sneezing
• Sore or scratchy throat
• Odynophagia (painful swallowing)
• Cough (from laryngeal swelling and post-nasal drip)
• Malaise
• Low-grade fever (more common in children)

Other less common symptoms may include:

• Foul breath
• Hyposmia (reduced ability to smell)
• Headache
• Shortness of breath
• Sinus pain
• Conjunctivitis (itchy and watery eyes)
• Nausea
• Vomiting
• Diarrhea
• Body ache

The symptoms of upper respiratory infections usually last 3-14 days; if symptoms last longer than 14 days, an alternative diagnosis can be considered, such as:

• Sinusitis
• Allergy
• Pneumonia
• Bronchitis

Bacterial pharyngitis (strep throat due to group A Streptococcus) may be considered if symptoms continue to worsen after the first week in the absence of a runny nose, cough or conjunctivitis. Prompt testing and initiation of appropriate antibiotics are important due to the risk of developing rheumatic fever, especially in children.

Epiglottitis is an upper respiratory infection in children that may have a more sudden onset of symptoms such as a sore throat, feeling a lump in the throat, muffled voice, dry cough, very painful swallowing and drooling.

Respiratory infections in the lower part of the upper respiratory tract, such as laryngotracheitis, are more commonly featured with dry cough and hoarseness or loss of voice. Barking or whooping cough, gagging and rib pain (from severe cough) are other symptoms and signs.

Most people tend to diagnose and treat their symptoms at home without seeking professional medical care. A great majority of cases of upper respiratory infection are caused by viruses and are self-limited, meaning they resolve on their own spontaneously.

Visiting a doctor may be advisable if

• Symptoms last more than a couple of weeks.
• Symptoms are severe and worsening.
• There is difficulty breathing.
• Swallowing is impaired.
• Upper respiratory infection is recurring.

Sometimes hospitalization may be necessary if the upper respiratory infection is severe and causes significant dehydration, respiratory difficulty with poor oxygenation (hypoxia), significant confusion, lethargy and worsening of shortness of breath in chronic lung and heart disease (chronic obstructive pulmonary disease or COPD, congestive heart failure). Hospitalizations are much more common in children less than 2 years of age, elderly people (especially those with dementia) and immunocompromised individuals (weak immune system).

In evaluating people with a suspected upper respiratory infection, other alternative diagnoses need to be considered. Some of the common and important diagnoses that can resemble an upper respiratory infection are:

• Asthma
• Pneumonia
• H1N1 (swine) flu
• Influenza
• Allergic reactions
• Seasonal allergies
• Chronic (long-standing) sinusitis
• Acute HIV infection
• Bronchitis

The diagnosis of an upper respiratory infection is typically made based on a review of symptoms, physical examination and occasionally, laboratory tests.

In a physical examination of an individual with an upper respiratory infection, a doctor may look for swollen and redness inside the wall of the nasal cavity (a sign of inflammation), redness of the throat, enlargement of the tonsils, white secretions on the tonsils (exudates), enlarged lymph nodes around the head and neck, redness of the eyes and facial tenderness (sinusitis). Other signs may include bad breath (halitosis), cough, voice hoarseness and fever.

Laboratory testing is generally not recommended in the evaluation of upper respiratory infections. Because most upper respiratory infections are caused by viruses, specific testing is not required, as there is typically no specific treatment for different types of viral upper respiratory infections.

Some important situations where specific testing may be important include:

• Suspected strep throat (fever, lymph nodes in the neck, whitish tonsils, absence of cough), which necessitates rapid antigen testing (rapid strep test) to rule in or rule out the condition, given the potential for severe sequelae if left untreated
• Possible bacterial infection by taking bacterial cultures with a nasal swab, throat swab or sputum
• Prolonged symptoms, as finding a specific virus can prevent unnecessary use of antibiotics (for example, rapid testing for the influenza virus from nasal or pharyngeal swabs)
• Evaluation of allergies and asthma, which can cause long-lasting or unusual symptoms
• Enlarged lymph nodes and sore throat as the primary symptoms that may be caused by the Epstein-Barr virus (mononucleosis) with an expected longer duration (detected using the monospot test)
• Suspected H1N1 (swine) flu, requiring testing

Blood work and imaging tests are rarely necessary for the evaluation of upper respiratory infections. X-rays of the neck may be done if there’s a suspected case of epiglottitis. Although the presence of a swollen epiglottis may not be diagnostic, its absence can rule out the condition. CT scans can sometimes be useful if symptoms suggestive of sinusitis last longer than 4 weeks or are associated with visual changes, copious nasal discharge or protrusion of the eye. A CT scan can determine the extent of sinus inflammation, the formation of an abscess or the spread of infection into adjacent structures (cavity of the eye or the brain).

As described above, most cases of upper respiratory infections are caused by viruses. Therefore, they require no specific treatment and are self-limited. People with upper respiratory infections typically diagnose themselves and treat their symptoms at home without requiring a doctor's visit or prescription medications.

Rest is an important step in treating upper respiratory infections. Usual activities, such as working and light exercising, may be continued as much as tolerated.

Increased intake of oral fluids is also generally advised to keep up with the fluid loss from a runny nose, fever and poor appetite associated with upper respiratory infections.

Upper respiratory tract infection treatments are usually continued until the infection has resolved.

Some of the most common upper respiratory tract infection medications or cold medications used to treat these symptoms are the following:

• Tylenol (acetaminophen) can be used to reduce fever and body aches.
• Nonsteroidal anti-inflammatory drugs such as Motrin or Advil (ibuprofen) can be used for body aches and fever.
• Antihistamines such as Benadryl (diphenhydramine) help decrease nasal secretions and congestion.
• Nasal ipratropium (topical) can be used to diminish nasal secretions.
• Cough medications (antitussives) can be used to reduce cough. Many cough medications are commercially available, such as Robitussin (dextromethorphan, guaifenesin) and codeine — all have shown benefits in reducing cough in upper respiratory infections.
• Honey can be used to reduce cough.
• Steroids such as Decadron (dexamethasone) and prednisone (orally or nasally) are sometimes used to reduce inflammation of the airway passage and decrease swelling and congestion.
• Decongestants such as Sudafed (pseudoephedrine), Actifed oral and Neo-synephrine nasal (phenylephrine) can be used to reduce nasal congestion (generally not recommended for children younger than 2 years and individuals with high blood pressure).
• Afrin (oxymetazoline) nasal solution is a decongestant but should only be used for the short term.
• Combination medications containing many of these components are also widely available over the counter.

Some cough and cold medicines that can cause excessive drowsiness need to be used with caution in children younger than 4 years of age and the elderly.

Broad-spectrum antibiotics are sometimes used to treat upper respiratory infections if a bacterial infection is suspected or diagnosed. These conditions may include strep throat, bacterial sinusitis or epiglottitis. Doctors may occasionally recommend antivirals for patients who are immunocompromised (poor immune system). The doctor can determine which antibiotic would be the best option for a particular infection.

Because antibiotic use is associated with many side effects and can promote bacterial resistance and secondary infections, they need to be used very cautiously and only under the direction of a treating physician.

Inhaled epinephrine is sometimes used in children with severe spasms of the airways (bronchospasm) and croup to reduce spasms.

Rarely, surgical procedures may be necessary in cases of complicated sinus infections, compromised airway with difficulty breathing, the formation of abscesses behind the throat or abscess formation of the tonsils (peritonsillar abscess).

By understanding the timeline of the upper respiratory infection and following the recommended treatment guidelines, individuals can manage the condition with confidence and take the necessary steps to facilitate a smooth recovery.

Upper respiratory infection timeline:

• Day 1-3 (incubation period): Symptoms may start 1-3 days after exposure.
• Day 3-10 (peak symptoms): Symptoms include cough, fever and runny nose.
• Day 10-14 (subsiding symptoms): Symptoms begin to subside; however, a dry cough may persist for 3-4 weeks.

Upper respiratory infection treatment guidelines:

• Symptomatic relief: Encourage rest, adequate hydration and over-the-counter medications such as acetaminophen or ibuprofen for fever and discomfort.
• Decongestants: Recommend oral or nasal decongestants to alleviate nasal congestion.
• Antitussives/expectorants: Administer cough suppressants or expectorants based on the severity of the cough.
• Antibiotics: These are not routinely recommended unless bacterial infection is suspected or confirmed. Avoid unnecessary antibiotic use to prevent antibiotic resistance.
• Antivirals: Antiviral therapy may be considered for severe cases or in high-risk individuals (for example, those who are immunocompromised or elderly).

• Rest and hydration: Continue to prioritize rest and hydration to support the body's natural healing process.
• Over-the-counter (OTC) medications: Utilize OTC remedies, such as decongestants, antihistamines or pain relievers to alleviate specific symptoms.
• Saltwater gargling: Gargling with warm salt water can help soothe a sore throat and reduce inflammation.
• Proper hygiene: Maintain good hand hygiene and respiratory etiquette to prevent the spread of infection.

• Medical Evaluation:
  • Seek medical attention if symptoms persist or worsen, or if there are breathing difficulties.
  • A health care provider may confirm the diagnosis through physical examination and possibly lab tests.
  • The treatment plan is adjusted based on clinical evaluation and patient response.

• Continued symptomatic relief and follow-up:
  • Symptoms begin to improve; continue with recommended symptomatic relief measures.
  • Follow up with the health care provider if symptoms persist or worsen.

• Gradual Recovery:
  • Symptoms gradually subside, but the cough may linger a few more days.
  • Emphasize the importance of hand hygiene, respiratory etiquette and avoiding close contact with sick individuals to prevent the spread of the infection.

Most upper respiratory infections are viral and self-limiting, so they typically resolve without the need for antibiotics. It's important to consult with a health care provider for a proper diagnosis and treatment plan.

The fastest way is to address the root cause of the infection. However, respiratory infections can vary in severity and cause, so treatment methods may also differ. To recover from a respiratory infection quickly, it’s important to take care of yourself and follow some home remedies that can alleviate your symptoms.

Here are some fast-acting remedies to get rid of respiratory infections:

• Rest: Adequate rest allows your body to focus its energy on fighting the infection. It also helps prevent the spread of the infection to others.
• Hydration:
  • Drink plenty of fluids, such as water, herbal tea or clear broth, to stay hydrated. This helps thin mucus secretions, making it easier to clear them from your respiratory tract.
  • Ginger has anti-inflammatory properties and can help relieve your symptoms. Add ginger to your tea or water and drink it once or twice a day.
  • Honey and lemon have antimicrobial properties. Mix honey and lemon in warm water, and drink it to soothe your cough and sore throat.
• Humidifier: Using a humidifier can help moisten the air you breathe, which may soothe irritated airways and ease congestion.
• Nasal irrigation: Nasal irrigation with saline solution can help clear mucus from the nasal passages and sinuses, reducing congestion and discomfort.
• Over-the-counter (OTC) medications: Depending on your symptoms, OTC medications such as pain relievers (such as acetaminophen or ibuprofen) and decongestants (such as pseudoephedrine or phenylephrine) may provide relief. However, consult a health care professional before taking any medications.
• Steam inhalation: Inhaling steam from a bowl of hot water or taking a hot shower can help loosen mucus and relieve congestion. Adding essential oils, such as eucalyptus or peppermint, may provide additional benefits.
• Gargling: Gargling with warm salt water may help soothe a sore throat and reduce inflammation.
• Proper hygiene: Practice good hygiene habits, such as washing your hands frequently, covering your mouth and nose when coughing or sneezing and avoiding close contact with sick individuals, to prevent the spread of the infection.

However, if your symptoms are severe, persistent or worsening, consult a health care professional for proper diagnosis and treatment.

Several self-care methods can simply be applied at home for relief of symptoms of an upper respiratory infection.

Moist warm air can help soothe the oral and nasal passages that become more irritated with dry air. This can make breathing easier and nasal secretions looser and easier to discharge. Some simple ways to do this are:

• Making steam in the shower by turning on the hot water (without going under it) and breathing the steamed air
• Drinking warm beverages (hot tea, hot chocolate, warm milk)
• Using a vaporizer to create humidity in the room
• Avoiding cold, dry air if possible

Nasal saline (salt water) can help with the symptoms of nasal congestion. Some over-the-counter saline spray solutions can be used for this purpose. Simpler and more cost-effective homemade saltwater solutions may also be considered. A fourth of a teaspoon of salt can be added to an 8 oz cup of room temperature water and stirred to dissolve. Using a bulb syringe or a small spray bottle, the solution may be applied in one nostril at a time with slow inhalation and expelled with exhalation several times a day as needed.

Applying a warm pack (a warm well towel or washcloth) to the face may also be used to treat symptoms of nasal congestion. This can be repeated every few hours as needed to relieve the symptoms.

Saltwater gurgles and lozenges may reduce throat irritation and dryness and can alleviate the symptoms of throat symptoms.

Cough can be suppressed by limiting exposure to irritants, such as cold weather, cigarette smoke, dust, and pollution. Sleeping in a semi-upright position may be helpful at times to reduce cough. A study has suggested that honey may be superior to dextromethorphan in reducing cough in children with an upper respiratory infection.

Adequate hydration with water, juices, and non-caffeinated drinks can thin nasal secretions and replace fluid losses.

Many alternative and cultural remedies are used in treating upper respiratory infections.

Herbal teas including elm bark and licorice root are thought to relieve sore throat, and some studies have suggested benefits compared to placebo. Long-term use of these remedies has not been evaluated; however, prolonged use of licorice may cause elevation of blood pressure.

As noted above, honey has been shown to be beneficial in suppressing cough in children with an upper respiratory infection, and its use in hot water or tea with lemon juice is not uncommon. Ingestion of honey in infants, however, is not recommended, as they are not able to properly digest the spores in honey, which can result in infections.

Echinacea is another herbal remedy commonly used in treating upper respiratory infections. Research data failed to prove any significant benefit in altering the duration and severity of upper respiratory infection symptoms when Echinacea was used in children between 2 and 11 years of age as compared to placebo.

Oral zinc supplementation has been used in recent years to reduce the duration and severity of symptoms of upper respiratory infections and the common cold. This therapy has been studied in children with upper respiratory infections, and the results are mixed. The FDA has not approved the use of oral zinc to treat the common cold or upper respiratory infections. There are reports of nausea and unpleasant taste caused by oral zinc.

Topical nasal zinc products, such as Zicam nasal gel, have been also used to attenuate the symptoms of upper respiratory infection. Some studies suggest the loss of the sense of smell (anosmia) associated with the use of this over-the-counter product. Therefore, the FDA recommended discontinuation of the use of intranasal zinc products in 2009.

The use of oral vitamin C is thought to shorten the duration of upper respiratory infection symptoms, but research data is inconclusive regarding the benefits of vitamin C.

In most cases, upper respiratory infections resolve within 1 to 3 weeks (7 to 21 days). However, some symptoms, such as cough and congestion, may persist for longer periods, even after the infection has cleared. The duration of your infection may vary depending on factors such as the type of virus, the strength of your immune system and whether you've taken any measures to support your recovery. If your symptoms persist beyond 2 weeks, it is recommended to consult your health care provider to rule out serious conditions such as pneumonia or bronchitis. Staying hydrated, getting plenty of rest and using over-the-counter remedies can all help you feel more comfortable as your body fights off the infection.

Some of the common complications of upper respiratory infections include:

• Respiratory compromise from epiglottitis
• Secondary infection by bacteria (viral infection can cause impairment of the physical barrier in the respiratory airways, making it easier for bacteria to invade) resulting in bacterial sinusitis, bronchitis and pneumonia)
• Formation of abscesses in the tonsils
• Rheumatic fever from strep throat
• Spread of infection from sinuses to the brain (meningitis)
• Involvement of the ears resulting in middle ear infections (otitis media)
• Worsening of underlying chronic lung disease (asthma, chronic obstructive pulmonary disease)
• Spread of the infection to the heart (pericarditis, myocarditis)
• Spread of the infection to the brain or the fluid around the brain, causing encephalitis or meningitis
• Muscular pain and rib fractures from forceful coughing

There are several measures that can reduce the risk of infections in general. Quitting smoking, reducing stress, having an adequate and balanced diet and exercising regularly are all measures that can improve the immune system and reduce the overall risk of infections. Breastfeeding also helps strengthen the immune system of infants by transferring the protective antibodies from the mother's milk to the baby.

Here are other preventive measures to diminish the risk of upper respiratory infections:

• Handwashing is especially encouraged during the cold seasons (fall and winter) or when handling others with the infection
• Reducing contact with people who may have the infection (people may carry and spread the virus a few days before the onset of symptoms and a few days after their symptoms have resolved)
• Proper cleaning of common objects (such as telephones, refrigerator doors, computers, stair railings, door handles, etc.) that may be touched by individuals who may be infectious
• Covering the mouth and nose when coughing or sneezing
• Vaccination with flu vaccine, as recommended for certain people (elderly, people with chronic medical conditions, health care workers, etc.)

In general, the outcome of upper respiratory infection is good. The majority of these cases are due to viral infections that are self-limiting. Bacterial infections, people with weak immune systems and those with complications of upper respiratory infections (listed above) may have a less favorable prognosis.