What is a cold?
The common cold is the illness that most often strikes the human body. On average adults contract it two to four times a year while children can get colds from three to eight times a year.
A cold is a mild viral infection of the upper or lower respiratory system (consisting of the nose, throat, ears and lungs). There are more than 200 different virus types that cause the common cold, which occurs when a virus infects the mucous membranes in the respiratory system. 2
Colds start slowly and progress over time. Symptoms are not radical and most colds are over within about five days. Typical symptoms include:
- A blocked nose
- A runny nose
- Sore throat
- Cough 2
The telltale sign of a full-blown cold is a watery and then a darker yellowish discharge.
With flu symptoms the onset is faster than with colds. Symptoms take from one to three days to develop and the disease can spread rapidly. It takes five to seven days to overcome but recovery can take as long as one to two weeks. Fever and other more severe symptoms distinguish flu from colds and include:
- Body aches and pains
- Fever or chills
- Loss of appetite
- Flushed face
- Nausea and/or vomiting
- Diarrhoea (more common in children)
- Congested nose
- Excessive sweating
- Sudden fever of 38 – 400C
- Unproductive cough
- Sore throat and sneezing 3
Cold and flu viruses are passed on from one person to another by direct or indirect contact. Direct contact occurs when the infected person sneezes. Tiny droplets of fluid containing the cold virus launch into the air and are breathed in by an uninfected person. Indirect contact occurs when you touch a door handle or a rail on which a person infected with a cold has already deposited the virus after sneezing or coughing. 3
Limit your risk by:
- Drinking water at regular intervals
- Eat enough vegetables and fruit
- Using a tissue (not a hanky) to wipe your nose and throw it away after use (2)
- Sneezing into a tissue and cover your mouth and nose when sneezing
- Washing your hands regularly with soap and water (3)
- Not sharing food or sharing eating utensils (3)
- Not putting your hands on escalator rails in shopping malls
- Trying to avoid contact with infected people in the first two to four days (2;3;4)
- Trying to avoid crowded places (3)
- Keep warm and move around to keep your body temperature up, particularly in winter
- Avoid touching your eyes and nose
- Getting vaccinated before flu season starts (2;3;4)
- Make sure that you drink plenty of clear fluids (water and clear, pure fruit juice) to help your body to fight the infection.
- Get plenty of rest and do not overexert yourself.
- Eat nutritional, light meals that are low in fat, high in fibre and contain plenty of fresh fruit and vegetables.
A virus is a microorganism (a very small organism), much smaller than bacteria. A virus can only reproduce in a living body cell whereas bacteria can live independently (grow and reproduce on their own). 1 Unlike bacteria, viral infections such as colds and flu cannot be countered or cured by antibiotics. 3;4 Rather, your body’s immune system must counter a viral infection. 3;4
Antibiotics are prescribed by a medical practitioner to prevent the onset of a secondary bacterial infection such as sinusitis and bronchitis. Common side effects related to antibiotic usage include diarrhoea and yeast infections.3;4 This can be minimized by taking a probiotic supplement or foods rich in probiotics such as yoghurt on an empty stomach or an hour before taking your antibiotic dose. Ask your medical practitioner to add this to your script.
Consult your medical practitioner if, once you seem to have recovered, you suddenly display any of the following symptoms: 3
• Difficulty breathing or shortness of breath
• Pain or pressure in the chest or abdomen
• Sudden dizziness
• Severe or persistent vomiting
• Flu-like symptoms that improve but then
• Return with fever and worse cough
You should also consult your medical practitioner if you suffer from a chronic condition such as:
• Heart, lung, kidney or liver disease
• If your immune system is compromised or
• If you fall within a high risk group (babies, elderly or frail)
• If you are pregnant or breastfeeding
People in high-risk groups are often advised to get flu injections before the onset of winter. Discuss this option with your medical practitioner. 3
References – Further Reading:
1. Solomon, Berg & Martin. 2007. Biology 8th ed. Cengage Learning. Page 500-503.
2. NIH (National Institute of Allergy and Infectious Disease) http://www.niaid.nih.gov/topics/commoncold Accessed February 2014
3. CDC (Centre for Disease Control and Prevention): http://www.cdc.gov/flu/index.htm Accessed February 2014
4. FDA (U.S. Food and Drug Administration) http://www.fda.gov/forconsumers/consumerupdates/ucm092810.htm Accessed February 2014