Anyone who has ever had a cold knows about acute respiratory infections (URIs). An acute URI is a contagious infection of your upper respiratory tract. Your upper respiratory tract includes the nose, throat, pharynx, larynx, and bronchi.
Without a doubt, the common cold is the most well-known URI. Other types of URIs include sinusitis, pharyngitis, epiglottitis, and tracheobronchitis. Influenza, on the other hand, isn’t an URI because it’s a systemic illness.
Both viruses and bacteria can cause acute URIs:
- coxsackie virus
- parainfluenza virus
- respiratory syncytial virus
- human metapneumovirus
- group A beta-hemolytic streptococci
- group C beta-hemolytic streptococci
- Corynebacterium diphtheriae (diphtheria)
- Neisseria gonorrhoeae (gonorrhea)
- Chlamydia pneumoniae (chlamydia)
The types of URIs refer to the parts of the upper respiratory tract most involved in the infection. In addition to the common cold, there are other types of URIs:
Sinusitis is inflammation of the sinuses.
Epiglottitis is inflammation of the epiglottis, the upper part of your trachea. It protects the airway from foreign particles that could get into the lungs. Swelling of the epiglottis is dangerous because it can block the flow of air into the trachea.
Laryngitis is inflammation of the larynx or voice box.
Inflammation of the bronchial tubes is bronchitis. The right and left bronchial tubes branch off from the trachea and go to the right and left lungs.
The common cold is the most common cause of doctor visits in the United States. URIs spread from one person to another through aerosol droplets and direct hand-to-hand contact. Risk goes up in these situations:
- When someone sick sneezes or coughs without covering their nose and mouth. Droplets containing the viruses are sprayed into the air.
- When people are in a closed-in area or crowded conditions. People who are in hospitals, institutions, schools, and day care centers have increased risk because of close contact.
- When you touch your nose or eyes. Infection occurs when the infected secretions come in contact with your nose or eyes.
- During the fall and winter (September to March), when people are more likely to be inside.
- When humidity is low. Indoor heating favors survival of many viruses that cause URIs.
- If you have a weakened immune system.
A runny nose, nasal congestion, sneezing, cough, and sputum production are the hallmark symptoms of URIs. Symptoms are caused by inflammation of the mucous membranes in the upper respiratory tract. Other symptoms include:
Most people with URIs know what they have. They may visit their doctor for relief from symptoms. Most URIs are diagnosed by looking at a person’s medical history and doing a physical exam. Tests that may be used to diagnose URIs are:
- Throat swab. Rapid antigen detection can be used to diagnose group A beta-hemolytic strep quickly.
- Lateral neck X-rays. This test may be ordered to rule out epiglottitis if you have difficulty breathing.
- Chest X-ray. Your doctor may order this test if they suspect pneumonia.
- CT scan. This may be used to diagnose sinusitis.
URIs are mostly treated for relief of symptoms. Some people benefit from the use of cough suppressants, expectorants, vitamin C, and zinc to reduce symptoms or shorten the duration. Other treatments include the following:
- Nasal decongestants can improve breathing. But the treatment may be less effective with repeated use and can cause rebound nasal congestion.
- Steam inhalation and gargling with salt water are a safe way to get relief from URI symptoms.
- Analgesics like acetaminophen and NSAIDs can help reduce fever, aches, and pains.
The best protection against URIs is frequent hand washing with soap and water. Washing your hands reduces exposure to secretions that can spread infection. Here are a few other strategies:
- Avoid being in close contact with people who are sick.
- Wipe down objects such as remote controls, phones, and doorknobs that may be touched by people in the house who have a URI.
- Cover your mouth and nose if you’re the one who is sick.
- Stay home if you’re sick.