Colds 

he vast majority of colds are caused by viruses. As many as 200 types of virus can cause common colds. The human immune system takes action to resist viruses as soon as they enter the body, and this resistance is termed immunity. When a person's immunity is strong, that person's body can easily deal with cold viruses, but when one's immunity is weak, it is easy to come down with a cold. 

The following are symptoms of common colds: 
1. Coughing or the presence of small quantities of phlegm. 
2. Fever, chills, aching of the muscles and joints. 
3. Running of clear mucous from the nose, nasal congestion, an 

    itching throat, tears, frequent sneezing. 

      While many people consider colds to be only a small problem, in fact colds are highly contagious. Colds may lead to complications in persons with weak resistance, such as children and the elderly, and may even be life-threatening. It is hard to estimate how much medical and social resources are expended because of colds. To reduce your chance of getting a cold, strengthen your immune system by maintaining correct living and eating habits.