The common cold is a viral infection of the upper respiratory tract (nose and throat) and it is characterized by sore throat, sneezing, and cough. Cold is among the most common illness of humankind and it is self-limiting, rarely cause additional health problems.

There are no subtypes for the common cold.

The most common cause is rhinovirus, other viruses that cause colds are adenovirus, enterovirus, coronavirus, parainfluenza virus, respiratory syncytial virus, etc. No clinical evidence suggests that colds are acquired by exposure to cold weather, getting wet, or get too cold.

• Preschool age due to hygiene issues (which is normal for child development)
• Increased interpersonal contact (e.g. indoors studying or military barracks)
• Low relative humidity of heated homes during the fall and winter
• Prematurity
• Infants who are not breastfed are at increased risk for severe disease
• Chronic lung disease, asthma—the duration of illness may be longer and with more severe symptoms
• Immunocompromise
• Reduced sleep duration (less than 7 hours)
• Depression
• Stress

Colds can spread in three ways:

1. Direct contact—kissing, hugging, holding hands with the person infected.
2. Indirect contact—touching something that has been touched by an infected person, e.g., doorknob, a toy or a used tissue.
3. Through the air—when the infected person sneezes or coughs. Droplets can reach another person's nose and mouth.

Inflammatory mediators cause vasodilatation, increased vascular permeability, and exocrine glands secretion which all lead to cold symptoms.

Clinical studies indicate sinus involvement in common cold. Abnormal computed tomography findings are present in adults that resolve over 1—2 weeks without antibiotic therapy.

• Sore or scratchy throat is frequently reported as the first manifestation
• Runny or blocked nose develop rapidly and are the most bothersome symptoms after 2—3 days
• Sneezing
• Coughing generally develops later and is the most bothersome symptom as the cold resolves
• Headaches
• Pressure in the ears and face
• Loss of appetite, taste, and smell
• Fatigue
• Mild fever
• Body aches

In children duration of cold can be up to 10—14 days, in adults it is mostly 7—10 days.

Diagnosis of the common cold is based on history and physical examination. Physical examination findings may be minimal but may include fever, nasal discharge, erythema of the nasal mucosa, and anterior cervical lymphadenopathy. Abnormal middle ear pressures are common, the tympanic membrane may be opaque or red without bulging.

Routine laboratory evaluation is not useful in the diagnosis of the common cold, although viral culture or polymerase chain reaction (PCR) is available for diagnosis in some locations and may be appropriate in some patients.

There are no antiviral agents currently available that are effective against the cold. Antibiotics are not effective against those viruses and do not prevent form complication development.

Lifestyle measures that can improve your feeling:

• Drinking plenty of fluids—water is the best possible choice, but it can be juice or lemon water as well. Avoid caffeine and alcohol.
• Warm fluids and soup can loosen congestion.
• Rest at home—stay at home from work and school. You will be able to rest and prevent others from getting sick as well.
• Keep your room warm and use a cool-mist humidifier or vaporizer, if the air is dry.

Treatment is supportive and it may ease the symptoms but it will not make the cold go away faster, the possible medication is listed below:

• Nasal (topical) decongestants
• Oral decongestants
• Nonsteroidal anti-inflammatory agents
• Antihistamines
• Saline nasal wash
• Vitamin C (ascorbic acid)
• Oral zinc
• Cough medications

Second bacterial infections include sinusitis, otitis media, and pneumonia. Acute otitis media may be present in one-third of colds in children. Exacerbations of asthma and chronic bronchitis are also important complications of the common cold.

A person with a cold can start infecting others a few days before symptom onset until total symptom disappearance. You can protect yourself by:

• Washing your hands with water and non-antibacterial soap for 20 seconds
• Avoiding to touch your eyes, nose, and mouth with unwashed hands
• Not sharing towels and household goods and products with an infected person
• Staying away from people with cold
• Doing exercises, eating well, having enough sleep and reducing stress

You can protect others if you have a cold by:

• Staying at home while you are sick
• Avoiding close contact with others (shaking hands, hugging, kissing)
• Moving away from others before coughing or sneezing
• When coughing or sneezing, completely cover your mouth and nose by the tissue and discard it right away or do it into your upper shirt sleeve
• Washing your hands after sneezing, blowing nose or coughing
• Not sharing drinking glasses and utensils with others
• Definfecting commonly touched surfaces, such as doorknobs

The common cold generally has little medical significance. The illnesses are frequently complicated by otitis media or sinusitis.

According to the publication by University of Virginia School of Medicine in Charlottesville, adults have an average of 2—3 colds per year, babies and toddlers even have 8—10 colds per year until they turn 2 years old. Kids in preschool age have 9 colds per year, but kindergartners can have even 12 colds in a year.

The incidence in adults is higher who have occupational exposure to children. If the climate is temperate, colds occur year round, but peaks are seen between the early autumn and late spring.