The common cold is usually caused by viruses, which are very small infectious agents. These viruses can be spread through the air when an infected person sneezes, coughs, or talks. They can also be spread through contact with contaminated objects or surfaces, such as doorknobs, countertops, or toys.

There are over 200 different viruses that can cause the common cold, but the most common are rhinoviruses. Rhinoviruses are responsible for about 30-50% of all colds. Other common causes of the cold include coronaviruses, adenoviruses, and parainfluenza viruses.

The symptoms of the common cold can include:

• Runny nose

• Congestion

• Sneezing

• Sore throat

• Cough

• Headache

• Muscle aches

• Fatigue

Most colds will go away on their own within 7-10 days. However, some colds may last longer or lead to more serious complications, such as bronchitis, pneumonia, or ear infections.

There is no specific cure for the common cold. Treatment is focused on relieving symptoms and making the person feel more comfortable. Over-the-counter medications, such as pain relievers, decongestants, and antihistamines, can help to relieve some of the symptoms of the cold. Rest, drinking plenty of fluids, and avoiding close contact with others can also help to speed up recovery.