What Is an Upper Respiratory Infection (URI)?
Picture of the upper and lower respiratory tract
- The respiratory tract is divided into two categories based on anatomy:
- The upper respiratory tract includes the mouth, nose, sinus, throat, larynx (voice box), and trachea (windpipe). Upper respiratory infections are often referred to as "colds."
- The lower respiratory tract includes the bronchial tubes and the lungs. Bronchitis and pneumonia are infections of the lower respiratory tract.
- The "common cold" is usually caused by a viral infection and treatment is directed at managing symptoms while the body's own immune system fights the infection. Common symptoms of an upper respiratory infection such as a cold include a runny nose, post-nasal drip, cough, and nasal congestion. If laryngitis develops (larynx=voice box + itis=inflammation), the patient may lose their voice or become hoarse.
- It is often difficult to know the difference between an acute upper respiratory infection and influenza (seasonal flu).
- However, influenza tends to cause symptoms and complaints that involve the entire body, including:
- Muscle aches and pains
- General malaise or feeling poorly
- Colds tend not to have such broad body system involvement. If the health care practitioner is concerned about the diagnosis of influenza (flu), antiviral medications may be prescribed. There are no specific antiviral medications to treat the common cold.
What Are Upper Respiratory Infection Symptoms and Signs?
Symptoms of the common cold may include:
- Stuffiness (nasal congestion), runny nose, low-grade fever, post-nasal drip, and cough:
- Dry cough (no sputum from the lung is being produced)
- With post-nasal drip, the cough may bring up some of the nasal secretions that have dripped into the back of the throat
- Sinusitis symptoms such as fullness in the face, increased nasal drainage, and occasionally pain and fever
In some infants and children, the upper airways may become inflamed causing croup (laryngotracheobronchitis, acute LTB). In addition to runny nose and stuffiness, the upper airways, especially the larynx can become inflamed causing a croupy or "barking cough."
What Causes Upper Respiratory Infections?
People catch colds when they come into contact with airborne viruses. Most often, the virus spreads from person to person in respiratory droplets from sneezing or coughing. Transmission of viruses can also occur due to poor hand-washing techniques. An infected person may shed viral particles onto their hands and then pass on these particles to someone else through a handshake or by handing them an object such as a pen or credit card. The second person then touches their own nose, eyes, or mouth, thereby acquiring the virus. Some viruses can live on surfaces such as sink faucets, door and drawer handles, table surfaces, pens, and computer keyboards for up to two hours, providing another way of spreading the infection.
People should understand that upper respiratory infections are contagious and are spread from person to person. Individuals are infected with the virus before symptoms arise and are therefore potentially contagious even before they know they are ill. Thus, hygienic measures such as covering sneezes and coughs, and regular hand washing should be a habit practiced by everyone even when not ill.
Rhinovirus ("rhino" from the Greek word for the nose) and coronavirus are the two most common viruses causing upper respiratory infections. Other viruses including parainfluenza virus, respiratory syncytial virus, and adenovirus can cause colds but may also cause pneumonia, especially in infants and children.
What Are the Risk Factors for Upper Respiratory Infections?
Not everybody exposed to or who comes into direct contact with an ill person will catch a cold. People are especially susceptible if there is a decrease in the body's immune system so that the virus can begin to spread within the body and cause symptoms in the body.
When Should You Call a Doctor for an Upper Respiratory Infection?
Most patients with acute upper respiratory infections will have a self-limited illness with symptoms resolving in a few days. Depending upon circumstances and symptom progression, some patients should seek medical care.
- Fever, chills, and shortness of breath are not commonly seen with upper respiratory infections and may signal a potentially more significant infection such as influenza, pneumonia, or acute bronchitis.
- Patients who are pregnant, under 2 years of age, or who have underlying illnesses such as asthma or emphysema should seek medical care if they experience shortness of breath.
- Nausea, vomiting, and diarrhea are not usually associated with an acute upper respiratory infection; however, further evaluation by a healthcare practitioner may be necessary if these symptoms occur.
- Although infants often catch colds, babies less than 3 months of age who develop fever should be seen immediately by a healthcare practitioner because their immune system is not yet fully developed and other infections may be present.
- Patients who are immuno-compromised due to medications or illness should contact their healthcare practitioner if they develop a fever, even if it seems to be due to an upper respiratory infection.
Most colds resolve within a week. If symptoms persist, it may be an indication to seek medical evaluation.
How Are Upper Respiratory Infections Diagnosed?
Medical History and Physical Examination
A diagnosis of a cold or upper respiratory infection is usually made by history and physical examination. The healthcare practitioner may ask questions in regard to the onset and duration of symptoms. The physical examination may concentrate on the head, neck, and lungs.
- Examination of the ears may reveal fluid behind the ear drums suggesting Eustachian tube swelling due to the cold. A nasal examination may show a clear discharge and a throat examination may reveal some redness and post-nasal drip.
- If the health care practitioner suspects sinusitis, he/she may use their fingers to tap on the face in areas overlying the large sinuses; the forehead for the frontal sinuses and the cheeks for the maxillary sinuses.
- The neck may be palpated or felt exploring swollen lymph nodes associated with an infection.
- The lungs may be assessed with a stethoscope to listen for wheezing (a whistling noise) or crackling sounds, both signs of inflammation or infection.
Imaging and Testing
Few tests are required for the diagnosis of an upper respiratory infection.
- If a strep throat infection is suspected, a rapid strep test or throat culture may be performed.
- If sinusitis is suspected, plain X-rays of the sinus structures may be ordered to check for air-fluid levels or clouding of the sinuses consistent with infection. Under some circumstances, a limited CT scan of the sinuses may be ordered to look for infection. Antibiotics may be prescribed if there is fever, facial pain, and a purulent (yellowish green) discharge from the nose indicating a bacterial component to the sinusitis.
What Home Remedies and Over-the-Counter Medications Treat Upper Respiratory Infections?
The treatment of upper respiratory infections often is directed at symptom control while the body fights the virus causing the infection. Antibiotics are not effective against viruses and are usually not prescribed unless the health care practitioner believes that a bacterial infection is present in addition to the cold.
Home Remedies and OTC Medications
- Drink plenty of fluids to prevent dehydration, and also to moisten the nose and sinus membranes.
- An air humidifier to keep the air moist will assist in keeping the nose and sinus membranes moist. However, use caution to avoid scalding burns due to hot water when humidifying the air. Cool mist humidifiers may be a better option.
- Acetaminophen or ibuprofen may be used to relieve minor fevers or facial soreness.
- Aspirin should not be used in children or teenagers because of the risk of Reye's syndrome.
- According to the American Academy of Pediatrics, over-the-counter (OTC) cold medications should not be used in infants and children because of their lack of effectiveness in controlling symptoms and the potential for significant side effects.
- For infants with stuffy noses, saline nose drops used with a bulb syringe may be helpful in clearing the nasal passages.
- Over-the-counter cold medications should be used with caution in adults as well. These preparations may contain multiple active ingredients that can increase blood pressure, cause heart palpitations, and promote sleepiness. Alcohol is one of the active ingredients in many OTC cold medications.
- Read the labels before taking any medications and discuss any questions or concerns with a pharmacist or health care practitioner in regard to potential side effects.
- Alternative treatments such as vitamin C, echinacea, and zinc have been used by some individuals; however, their benefits have not been scientifically proven.
What Medications or Antibiotics Treat Upper Respiratory Infections?
Medications are usually not prescribed for upper respiratory infections. Antibiotics are not effective in fighting viral infections. However, antibiotics are appropriate if the health care practitioner suspects that a bacterial infection exists, for example in cases of otitis media (ear infections), bacterial sinusitis, and strep throat.
In some cases, where there is significant inflammation of the upper airways, for example, croup in infants and children, corticosteroid medications such as prednisone (Meticorten, Sterapred, Sterapred DS) or dexamethasone (Decadron, AK-Dex, Ocu-Dex) may be prescribed to decrease that inflammation.
What Are the Complications of Upper Respiratory Infections?
Most colds resolve on their own with few complications. Sometimes, the inflammation caused by the upper respiratory infection may cause drainage problems within the sinuses or the middle ear, which can create the potential of secondary bacterial infections such as sinusitis or otitis media.
If not enough fluid is taken, dehydration is always a potential complication of infection.
How Long Do Upper Respiratory Infections Last? Is There a Vaccine?
Most upper respiratory infections resolve within a few days and no follow-up is required. Upper respiratory infections are a common occurrence and most people will get 2-4 colds per year. Research continues seeking vaccines and treatments that can lessen the symptoms of a cold and perhaps decrease the number of infections a person will get each year.
How Can You Prevent Upper Respiratory Infections?
We live in a social world in which people come into close contact with others every day.
Upper respiratory infection prevention includes:
- Avoiding people who are ill
- Staying at home if you are ill until you are no longer contagious
- Not touching your nose, eyes, and mouth with unwashed hands
- Covering your cough and sneeze; sneezes and coughs should be covered with the elbow or sleeve and not the hand
- Washing your hands often and properly (20 seconds or more with soap and warm water)
- Making lifestyle changes through smoking cessation and stress management, which can decrease your susceptibility to catching a cold.
Reviewed on 10/18/2022
"Common Cold." NIH.