Viral Respiratory Tract Infection

Viral respiratory infections are among the most common illnesses worldwide, affecting millions of people each year and leading to thousands of hospitalizations. These infections impact the parts of your body involved in breathing and can range from mild colds to more serious conditions requiring medical care.

Table of contents

• What is a viral respiratory infection
• Symptoms
• Causes and how infections spread
• Who is at higher risk
• Diagnosis
• Treatment and home care
• Prevention strategies
• When to seek medical help

What is a viral respiratory infection

A viral respiratory infection is an illness of the nose, sinuses, throat, airways, or lungs caused by a virus. These infections are typically divided into two main types based on where they affect your breathing system^[1][2].

Upper respiratory tract infections affect the parts of your breathing system above your vocal cords, including your nose, sinuses, throat, and voice box. Common examples include the common cold, sinus infections, and sore throats^[2].

Lower respiratory tract infections affect the parts below your vocal cords, including your windpipe, airways, and lungs. Examples include bronchitis and pneumonia. Some viruses that start in the upper respiratory tract can progress to cause serious lung infections^[1][2].

In the United States alone, respiratory viruses are responsible for millions of illnesses each year. Last year, at least 1 million people were hospitalized and more than 70,000 people died from respiratory virus illnesses^[1].

Symptoms

The symptoms of a viral respiratory infection often start quickly and can affect different parts of your breathing system^[1][4].

Symptoms affecting your respiratory tract may include^[1][3]:

• Runny or stuffy nose
• Sneezing
• Sore throat
• Cough, which may produce mucus
• New loss of taste or smell
• Breathlessness, tight chest, or wheezing

Other possible symptoms that may accompany respiratory infections include^[1][3]:

• Fever or feeling feverish
• Chills
• Headache
• Muscle or body aches
• Fatigue and tiredness
• Weakness
• Decreased appetite
• Feeling generally unwell
• Vomiting or diarrhea

Most viral respiratory infections pass within 1 to 2 weeks. You will probably feel better in 4 to 10 days^[3][4].

Causes and how infections spread

Viruses cause most respiratory infections. Many different types of viruses can infect your respiratory tract^[2][6].

Common viral causes include^[1][2]:

• Flu (influenza viruses)
• COVID-19 (SARS-CoV-2 virus)
• Respiratory syncytial virus (RSV), which is a virus that commonly affects the breathing system, particularly in young children and older adults
• Rhinovirus and enterovirus (common cold viruses)
• Adenovirus
• Parainfluenza viruses
• Coronaviruses
• Human metapneumovirus

Viruses that cause respiratory infections are highly contagious and spread from person to person in several ways^[2][3]:

• Through respiratory droplets when someone coughs, sneezes, or talks
• By sharing eating or drinking utensils like forks, spoons, cups, or water bottles
• Through contact with objects or surfaces that have germs on them, such as doorknobs, light switches, phones, or toys

Most often, viral respiratory infections spread when people’s hands come into contact with nasal secretions from an infected person. When they then touch their nose or eyes, the viruses gain entry and produce a new infection^[9].

Contrary to what many people believe, becoming chilled, wet, or tired does not cause colds or increase your susceptibility to infection^[9].

Who is at higher risk

Respiratory illnesses can make anyone sick. Even healthy people can get very sick from respiratory illnesses. However, some people have risk factors that can increase their chances of getting very sick, which is called severe illness^[1].

People at higher risk include^[1]:

• Adults who are 65 years and older
• Children younger than 2 years old
• Newborns
• People with medical conditions such as chronic lung disease, heart disease, diabetes, or chronic kidney disease
• People with a weakened immune system
• People with disabilities
• Pregnant women

Young children are typically more likely to spread respiratory infections than adults. When children are infected, their nasal secretions contain more viruses than those from infected adults. This increased output of viruses, combined with typically less attention to hygiene, makes children more likely to spread their infection to others. The possibility of transmission is further enhanced when many children are gathered together, such as in child care centers and schools^[9].

Diagnosis

Viral respiratory infections are typically diagnosed based on your symptoms and the pattern of illness in your community. For patient care, identifying the type of respiratory illness you have is usually sufficient. Identifying the specific virus is rarely necessary^[6].

Healthcare providers usually diagnose upper respiratory infections based on your symptoms and, when needed, tests such as nasal swabs or throat cultures. If your symptoms are mild and your tests are negative for infections like the flu or strep throat, you might have one of hundreds of common cold viruses, which providers don’t often test for^[2].

Diagnostic testing should be reserved for situations where knowing the specific virus affects your treatment, or when your healthcare provider needs to identify and control an outbreak^[6].

Several types of tests are available^[6]:

• Rapid point-of-care antigen tests are available for influenza, RSV, and COVID-19. These tests can give results quickly but are less sensitive than laboratory tests
• Laboratory tests based on detecting the virus’s genetic material are more sensitive and are preferred when available
• Tests are typically used when the result would affect treatment decisions or help prevent the spread of infection

Treatment and home care

Most viral infections can be treated with home care^[4][3].

Antibiotics are not used to treat viral infections. Antibiotics don’t kill viruses, so they won’t help cure a viral illness. They are only used to treat bacterial infections^[3][4].

For certain viruses, antiviral medications may be an option. Treatment for COVID-19 and flu can lessen symptoms and shorten the time you are sick. They may also reduce the risk of complications and hospitalization. Treatment needs to be started within a few days of when your symptoms begin. If you have risk factors for severe illness and develop symptoms, seek healthcare right away for testing and possible treatment^[16].

To care for yourself at home^[3][4]:

• Get plenty of rest
• Drink lots of water to loosen any mucus and make it easier to cough up. Choose water and other clear liquids
• Use over-the-counter pain medicine such as acetaminophen or ibuprofen to bring down a fever and help ease sore throat, headaches, and muscle pain. Be safe with medicines and read all instructions on the label
• Drink a hot lemon and honey drink to help soothe a cough (not suitable for babies under 1 year old)
• Gargle with warm salty water if you have a sore throat (children should not try this)
• Raise your head up while sleeping using extra pillows to make breathing easier and clear your chest of mucus
• Use saline nasal washes to help keep your nasal passages open and wash out mucus
• Use a vaporizer or humidifier to add moisture to your bedroom
• Do not smoke or allow others to smoke around you

Some treatments like decongestants and nasal sprays are available from pharmacies, although there’s little evidence to show that cough medicines and throat lozenges help significantly^[3].

Prevention strategies

There are actions you can take to help protect yourself and others from health risks caused by respiratory illnesses^[1][17].

Core prevention strategies that everyone should use include^[1][17]:

• Stay up to date with recommended vaccinations. Talk to your doctor or trusted healthcare provider about what may be recommended for you and your family. Vaccines are available for flu, COVID-19, and RSV for eligible groups
• Practice good hand hygiene by washing your hands regularly with soap and water for at least 20 seconds
• Clean commonly touched surfaces
• Take steps for cleaner air by bringing in fresh outside air, purifying indoor air, or gathering outdoors when possible
• When sick, use precautions to prevent the spread of illness and seek healthcare promptly for treatment if you have risk factors for severe illness

Additional prevention strategies can provide an extra layer of protection, especially when illnesses are increasing in your community or when you’re around people at higher risk^[17]:

• Wearing masks
• Physical distancing from others
• Using tests to detect infections

To reduce the chance of passing a respiratory infection to others^[3]:

• Cover your mouth when you cough or sneeze
• Wash your hands regularly
• Throw away used tissues immediately

When to seek medical help

You should stay home and away from others (including people you live with who are not sick) if you have respiratory virus symptoms. You can go back to your normal activities when, for at least 24 hours, your symptoms are getting better overall and you have not had a fever without using fever-reducing medication^[20].

When you go back to normal activities, take added precautions over the next 5 days, such as wearing a well-fitted mask, practicing physical distancing, and being especially careful around people at higher risk^[20].

See a healthcare provider if^[3]:

• You feel very unwell or your symptoms get worse
• You’ve had a high temperature for more than 3 days
• You cough up blood or bloodstained mucus
• You’ve had a cough for more than 3 weeks
• You’re pregnant
• You’re over 65
• You have a weakened immune system
• You have a long-term health condition such as heart, lung, or kidney disease

Call for emergency care if^[4]:

• You have severe trouble breathing
• You have a fever with a stiff neck or a severe headache
• You are sensitive to light
• You feel very sleepy or confused

You may have pneumonia if your symptoms are severe^[3].