Respiratory tract infection

Sometimes we get sick in our airways.

This can happen in our nose. It can also happen in our lungs.

An infection in the nose is often a cold. It can make you sneeze or cough. It might make your throat feel sore.

An infection in the lungs is more serious. It can be called pneumonia. These sicknesses can be very bad.

Some germs like the cold air in winter. Other germs like the warm summer.

We can stay well by being careful. It is good to learn how our bodies work.

An infection can happen in your airways. These are the paths you use to breathe.

Some infections happen in the upper respiratory tract. This part is above your vocal cords. It includes your nose, sinuses, and throat. A common cold is an upper infection. It can cause a cough or a runny nose. You might also have a sore throat or a headache.

Other infections happen in the lower respiratory tract. This part includes your windpipe and your lungs.

These infections are often more serious. Pneumonia is a common lower infection. These can be very dangerous. Some germs, like the flu, can affect both parts.

Doctors use many ways to help. They may use a chest x-ray to look at your lungs. They might use antibiotics to treat bacteria. Bacteria are tiny living things. However, antibiotics do not work on viruses. Using them when you do not need them can cause problems.

Many germs like the winter. In cold places, the air is often dry. This can help germs spread more easily.

Respiratory tract infections are illnesses that affect how we breathe. These infections happen in our airways, which are the paths for air. Doctors divide these illnesses into two main groups. The first group is called upper respiratory tract infections. These happen in the parts of the airway above the vocal cords. This area includes the nose, the sinuses, and the throat.

Common examples are the common cold or a sore throat. These can cause a runny nose, a cough, or a headache.

The second group is called lower respiratory tract infections. These happen deeper in the body. This area includes the trachea, which is the windpipe. It also includes the bronchial tubes and the lungs. These infections are often much more serious than upper ones. In fact, they are the leading cause of death from infectious diseases. Two common types are bronchitis and pneumonia. Some germs, like the H5N1 flu, can even travel deep into the lungs.

Doctors use special tools to see how the lungs are working. They might use Pulmonary Function Testing to check the airways. This helps them find specific benchmarks to diagnose an infection. Some methods, like gas dilution, help find the total lung capacity. In 2013, researchers even made a breath tester. This tool can quickly help diagnose lung infections. Doctors also use chest x-rays to look at the lungs in children.

Treating these infections can be a hard job for doctors. They use antibiotics to fight bacteria, which are tiny living things. However, antibiotics do not work on viruses like the flu. Using antibiotics when they are not needed can cause side effects. It can also lead to antibiotic-resistant infections. In 2018, there were 47 million antibiotic prescriptions in the United States for infections that did not need them.

Doctors suggest using narrow-spectrum medicines like amoxicillin to reduce side effects.

Many of these germs follow a seasonal pattern. In many places, infections peak during the winter. This happens because winter air is often very dry. Low humidity helps viruses like influenza spread more easily.

Some germs, like the common cold, appear in spring and fall. Other germs, like enteroviruses, often peak in the summer. Keeping indoor humidity between 40 and 60 percent may help reduce the risk of germs spreading through the air.

Respiratory tract infections (RTIs) are infectious diseases that affect the human respiratory system. These illnesses can target different parts of the airways used for breathing. Doctors generally classify these infections into two main categories based on their location. The first category is the upper respiratory tract infection (URI or URTI). The second category is the lower respiratory tract infection (LRI or LRTI). Understanding where an infection occurs is vital because the severity often depends on the location.

An upper respiratory tract infection affects the airway above the glottis, which are the vocal cords. Some experts define this area as the tract above the cricoid cartilage. This upper section includes several important structures: the nose, the sinuses, the pharynx, and the larynx. Common examples of these infections include the common cold, sinusitis, and laryngitis. Other types include tonsillitis, pharyngitis, and otitis media. Some influenza types also cause upper respiratory infections. Symptoms often include a runny nose, nasal congestion, sneezing, or a sore throat. Patients may also experience a headache, facial pressure, or a low-grade fever.

Lower respiratory tract infections occur deeper in the body. This area consists of the trachea, which is the windpipe, and the bronchial tubes. It also includes the smaller bronchioles and the lungs. LRIs are generally much more severe than upper respiratory infections. In fact, LRIs are the leading cause of death among all infectious diseases. Two of the most common lower respiratory infections are bronchitis and pneumonia. While influenza can affect the upper tract, dangerous strains like H5N1 are particularly pernicious. These specific strains tend to bind to receptors located deep within the lungs.

To diagnose these conditions, medical professionals use several different methods. Pulmonary Function Testing (PFT) allows doctors to evaluate and assess the airways and lung function. This testing helps establish specific benchmarks to diagnose various respiratory tract infections. Certain techniques, such as gas dilution and plethysmography, are used to determine total lung capacity. They also help determine the functional residual capacity of the lungs. In 2013, researchers developed a new tool called a breath tester. This device can promptly diagnose lung infections. In children, using rapid viral testing can reduce the relative risk of using chest x-rays by 77% compared to controls.

Treating these infections requires a careful distinction between bacteria and viruses. Bacteria are unicellular organisms that can thrive in many environments, including the human body. Antibiotics are medicines designed specifically to treat bacterial infections. However, antibiotics are not effective against viral infections like influenza or the common cold. This is because antibiotics target specific features of bacteria that viruses do not possess. Using antibiotics unnecessarily can be harmful. It can lead to antibiotic-resistant infections, digestive system issues, or allergic reactions. In 2018, the CDC reported that 47 million antibiotic prescriptions in the United States were for infections that did not require them.

Prevention and management strategies vary depending on the patient's environment. In intensive care units (ICU), adults face a higher risk of acquiring an RTI. For adults on mechanical ventilation for at least 48 hours, a combination of topical and systemic antibiotics may prevent infection. This combination can also improve overall mortality rates in the ICU. However, researchers are still studying whether topical antibiotic prophylaxis alone reduces mortality. For children under five, there is not enough evidence to recommend antibiotics to prevent complications from an RTI of unknown cause. Regarding physical barriers, there is insufficient clinical evidence to prove if standard surgical masks are equivalent to N95 respirators for preventing infections in healthcare workers.

Respiratory infections often follow strong seasonal patterns based on the environment. In temperate climates, infections often peak during the winter months. This is partly due to environmental conditions like temperature and relative humidity. Many viruses, such as influenza, human coronaviruses, and RSV, are more prevalent in the winter. Lower relative humidity in winter is known to increase the transmission of influenza. Conversely, enteroviruses tend to peak in the summer, while rhinoviruses often appear in the spring and fall. To help lessen the risk of aerosol transmission, it is recommended to keep indoor humidity between 40% and 60%.