The cold and flu are both respiratory illnesses with similar symptoms such as congestion and headaches and both are infections caused by viruses. The flu is caused by the influenza virus. A vaccine is produced for the most common influenza virus each year. A vaccine does not exist for the common cold since it is caused by many viruses including rhinovirus, adenoviruses, and coronaviruses. The cold is not as severe while the flu can be life-threatening. Around 200,000 people are hospitalized with the flu and 36,000 die of the flu every year in the U.S. Distinguishing the signs between these two conditions is an important part of the healing process and can help prevent hospitalizations.
One of the largest differences between the cold and flu is the body region in which the symptoms are localized. The head and chest are the affected regions with a cold. Symptoms include congestion, runny nose, coughing, sneezing, and sore throat. During a bout of the flu, the whole body is affected. In addition to the symptoms of a cold, flu presents with chills, muscle aches, fever, and fatigue. The symptoms of a flu are much more severe than those of a cold and they appear more quickly. The duration of a cold is shorter and lasts for a few days while the flu can last for weeks.
A cold can occur all year long while the flu tends to be seasonal. The flu season proceeds from fall to spring and peaks during the winter. Influenza A, B, and C viruses are the cause of seasonal flu and they often result in a fever above 100°F that can last 3 to 4 days. A fever associated with a cold is much milder and lasts 1 to 2 days. An internal temperature of 101°F typically indicates a flu.
Unlike a cold, the flu can lead to other health complications including pneumonia, bronchitis, and bacterial infections. Signs of pneumonia include chest pressure and discomfort; difficulty breathing; coughing with green mucus; sore throat; and a consistent high fever. Children, pregnant women, elderly, and individuals with pre-existing health conditions are at increased risk of developing these complications. Medical professionals should be notified if a flu is present in any of these at-risk individuals or if signs of complications are present.
Over-the-counter decongestants and pain relievers are effective at treating the symptoms of both illnesses. Antiviral medications can be prescribed to treat the flu. Frequent hand-washing and avoiding people with these illnesses are common ways to prevent them. The most effective way to prevent the flu is to obtain an annual flu vaccine.