Overview of the Common Cold and Cold Viruses
The common cold is an acute viral infection of the upper respiratory tract that affects the nose, throat, sinuses, larynx, and sometimes the lungs. Varieties of rhinovirus and coronavirus are the most common causes.
These viruses are easily transmitted through contact with the secretions of infected people (e.g., handshakes, shared objects, kissing). Once the virus enters the body, it multiplies in the cells (often at the back of the nose) and causes an inflammatory response that produces characteristic symptoms such as excessive mucus (probably in an attempt to rid the body of the virus) and swollen airways.
Incidence and Prevalence of the Common Cold
Adults average two colds a year and children typically get them more often.
Causes and Risk Factors for Common Cold
The common cold is transmitted through person-to-person contact, typically when an infected person touches the eyes, mouth, or inside of the nose and spreads the virus to the hands. Poor hygiene promotes infection. Kissing and sharing eating utensils with an infected person are common modes of transmission. Malnourishment and exposure to cold weather or rain do not cause a cold.
Common Cold Signs and Symptoms
Symptoms of a cold usually appear 36 to 72 hours after exposure. The first symptom to develop is usually irritation in the nose and throat, then nasal congestion, sore throat (pharyngitis), sneezing, coughing, and runny nose (rhinorrhea). Nasal secretions are thin and profuse initially, but become thick and yellow as infection progresses. Headache, body pain, and malaise also commonly occur, but fever is rare.
Cold symptoms are intensified by the following factors:
- Emotional distress
- Excessive fatigue
- Weakened immune system
Symptoms usually last 5 to 10 days and resolve without treatment in otherwise healthy people. Persistent, mild coughing is common following the resolution of acute symptoms and may last 2 weeks.
Cold complications include acute viral sinusitis (inflammation of the sinuses), coexistent bacterial infection, and lower respiratory infection (bronchitis).
Common Cold Diagnosis
Diagnosis of the common cold is typically made be observing symptoms and their course. Characteristic swelling of the nasal passages and throat can cause them to redden, which can be seen during examination. Lung examination performed with a stethoscope usually reveals normal function.
The throat can be cultured with a swab to differentiate the common cold from a bacterial infection, such as strep throat. Cultures are usually performed if the throat or tonsils are red, swollen, and have white spots of purulent exudate (pus); if fever is present; if the lymph nodes in the neck are swollen and tender; or if symptoms persist longer than expected.
Common Cold Treatment
Experimental vaccines have been used to treat certain types of rhinoviruses, but a vaccine is not available to treat the common cold. The goal of treatment is to relieve symptoms while the virus runs its course.
Although there are a number of over-the-counter (OTC) remedies available to relieve cold symptoms, these medications should not be used in children under the age of two, due to an increased risk for serious side effects. These drugs (e.g., antihistamines, decongestants, expectorants, cough suppressants) should only be used as directed in children between the ages of 2 and 11.
When used for a short time, decongestants and nasal sprays may shrink swollen airways, and antihistamines may reduce sneezing and runny nose. However, some people experience rebound congestion after using these treatments.
Acetaminophen (e.g., Tylenol) and ibuprofen (e.g., Advil) may help alleviate body pain, malaise, and headache. Warm, humid air (from a vaporizer or hot shower) helps ease breathing for most people.
Common Cold Prevention
Good hygiene is the best defense against getting a cold. Washing hands with soap and warm water can minimize the spread of infection.