An upper respiratory infection, also known as the common cold, is one of the most common illnesses, leading to more health care provider visits. Caused by a virus that inflames the membranes in the lining of the nose and throat, colds can be the result of more than 200 different viruses. Adults can get colds about 2 to 4 times a year.
There are many different types of viruses that cause a respiratory infection; over 200 different varieties of viruses can cause the symptoms of a cold. The most common viruses that cause colds are called rhinoviruses. Other types include coronavirus, parainfluenza, adenovirus, enterovirus and respiratory syncytial virus. After the virus enters your body, it causes a reaction – the body's immune system begins to react to the foreign virus causing:
The symptoms start 1 to 3 days after being in contact with the virus. Usually, the symptoms last about one week, but this can vary. The following are the most common symptoms of an upper respiratory infection:
Most are diagnosed based on reported symptoms, but these symptoms may be similar to certain bacterial infections, allergies, and other medical conditions.