Colds are often associated with low temperatures, with a so-called “cold snap,” but viral infections are usually involved.

The link with low temperature, however, exists: as temperatures drop, the activity of our immune system decreases, and we are more exposed to the action of viruses.

What Causes Colds?

A cold is a viral disease affecting the first respiratory tract, particularly involving the nose and throat, caused by more than 200 viruses. The most common are rhinoviruses, transmitted through contact with a person with colds.

The infection is mainly airborne; the virus is spread through tiny droplets of nasal secretion or saliva emitted through coughing, sneezing, or simply talking.

Many viruses last up to 18 hours outside an organism; therefore, an environment can remain infected for a long time. In contrast, on average, a person is most contagious in the first three days they develop symptoms.

People who run an increased risk of contracting colds are:

  • Children under the age of six, especially if they attend daycare centers and preschools;
  • People with a fragile immune system, for example, due to chronic illness or even mild immune system deficiency;
  • People who smoke.

What Are the Symptoms of Colds?

Usually, the symptoms of colds occur a few days after infection.

Some of the most common include:

  • Nasal respiratory obstruction;
  • Sore throat;
  • Sneezing;
  • Presence of mucus;
  • Coughing;
  • Hoarse voice;
  • Discomfort;
  • Fatigue.

In some cases, fever, headache, muscle ache, and reduced or loss of sense of smell and taste may be combined with the abovementioned symptoms. Irritation of the eyes and ears is not uncommon.

Symptoms tend to be more intense in the first two to three days, then fade and resolve completely within 7 to 10 days. The cough may persist for two to three weeks.

Cold-related symptoms may persist for up to 14 days in children under five years old.

Influenza and colds have similar symptoms; however, there are some differences.

First, they are caused by different viral agents that can cause nasal symptoms associated with headache and fever. In the case of influenza, other symptoms may also occur, such as muscle aches and asthenia, possibly hindering everyday activities. 

Complications of Colds

Colds usually resolve on their own without any particular after-effects.

Sometimes, however, the infection can spread to the lower airways, ears, or sinuses and cause complications, such as:

  • Sinusitis due to bacterial infection with the characteristic presence of yellow-green discharge, lasting more than ten days and also associated with facial pain;
  • Otitis media: particularly common in children under five years of age, it is a middle ear infection whose symptoms include earache, high fever above 38 °C and reduced hearing;
  • Lower airway infections such as bronchitis or pneumonia with persistent coughing and shortness of breath.

Colds: Greater Risk in Enclosed Places

During the colder months, it is essential to be careful about the quality of the air you breathe. People often spend much time indoors, in shared rooms, increasing the risk of contracting respiratory diseases.

The cold air from outside is less harmful to respiratory health than the stale air found indoors.

To reproduce, adenoviruses and Rhinoviruses need temperatures lower than the human body (between 96 and 98 °F). Once outside the human body, they spread through the air and can last up to 18 hours.

To prevent infection, washing hands often and using a face mask in exceptionally crowded places, such as public transportation, is essential.

How Do You Treat Colds?

Colds generally resolve spontaneously in 5-10 days, so it is possible to manage the symptoms independently, resorting, if needed, to medications such as painkillers and antipyretics to lower fever, if present, and decongestants to reduce nasal obstruction.

Because they are caused by a virus, not a bacterium, antibiotics are not effective for colds but are essential in case of complications with bacterial infection.

Rest and isolation are the best ways to help the body heal, preventing the virus from affecting others. Those with colds should, therefore, work from home, ventilate their rooms often, avoid crowded places such as public transportation, and cough and sneeze into the inner part of the elbow joint. If going outside is necessary, a mask should be worn to cover the nose and mouth.