What is an upper respiratory infection?

An upper respiratory infection, also known as the common cold, is one of the most common illnesses, often leading to a visit to your primary care physician for care. 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 two to four times a year.

Upper respiratory infection symptoms

Common cold symptoms start one to three 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 upper respiratory infection symptoms:

  • Stuffy, runny nose
  • Scratchy, tickly throat
  • Watery eyes
  • Sneezing
  • Mild hacking cough
  • Congestion
  • Sore throat
  • Achy muscles and bones
  • Headaches
  • Low-grade fever
  • Chills
  • Watery discharge from the nose that thickens and turns yellow or green
  • Mild fatigue

What causes an upper respiratory infection?

There are many different types of viruses that cause a respiratory infection. In fact, more than 200 different varieties of viruses can cause cold symptoms. The most common viruses that cause colds are called rhinoviruses. Other types include coronavirus, parainfluenza, adenovirus, enterovirus and respiratory syncytial virus (RSV). After the virus enters your body, it causes a reaction—the body's immune system begins to react to the foreign virus causing:

  • An increase in mucus production (a runny nose)
  • Swelling of the lining of the nose, making it hard to breathe and causing congestion
  • Sneezing from the irritation in the nose
  • A cough from the increased mucus dripping down the throat

Most upper respiratory infections are diagnosed based on reported symptoms, but these symptoms may be similar to certain bacterial infections, allergies and other medical conditions. Talk to your primary care doctor about your symptoms to determine the best upper respiratory infection treatment for you.