What is a cold?
The common cold (acute viral rhinopharyngitis, oracute coryza) is a viral infectious disease that infects the upper respiratory system.
It is your body’s reaction to the cold virus that contributes to most of the symptoms. When the viruses overpower your body's immune system, infection occurs. Mucus is produced in the nose and throat by the mucus glands as the body’s first line of defense. It traps anything inhaled, such as dust, viruses and bacteria. If the mucus is penetrated by the virus, the virus takes control of the element of the cell which makes protein. This allows it to manufacture more viruses, which then attack surrounding cells.
Common symptoms of a cold are:
- Dry throat
- Sore throat
- Mild fever
- Hoarse voice
- Blocked nose
- Mild headache.
In rare cases, people can also experience muscle aches, shivering, pink eye, weakness, reduced appetite and extreme exhaustion.
Around 25% of people don’t suffer any symptoms when they have the cold virus; perhaps because their immune system reacts differently to it. Sometimes, a cold can lead to bacteria infecting the ears or sinuses (a secondary bacterial infection). Unlike a cold, this can be treated with antibiotics.
A cold can lead to the following complications:
- Acute Bronchitis
- Acute Bacterial Sinusitis
- Otitis media
- Strep throat.
The Common Cold can exacerbate emphysema or chronic bronchitis symptoms. Asthma attacks can be caused by a cold, especially in children.
What is the flu?
It can be hard to tell if you have the flu or a bad cold. Flu symptoms are generally experienced sooner than cold symptoms and are more intense. The flu can make you feel weak and tired for up to two or three weeks. It can lead to fever and periods of chills and sweats (cold sweats), aching muscles, and a runny or clogged nose, headaches, a sore throat and coughing.
What a cough?
A cough is a sudden reflex to clear the throat and breathing passage of foreign particles, microbes, irritants, fluids and mucus. It involves is a rapid expulsion of air from the lungs. It can be done deliberately or involuntarily. Suppressing a natural reflex like coughing can be bad for you.
These are the classifications for coughs:
- Acute - this is a cough with a sudden onset that lasts up to 3 weeks.
- Subacute - this type of cough persists for between 3-8 weeks.
- Chronic - this type last for over 8 weeks.
- Productive - a cough that brings stuff up, such as sputum.
- Dry - a cough that brings nothing up.
- Nocturnal – one that only occurs at night.
What causes a cold?
The common cold is mainly caused by coronaviruses or rhinoviruses (responsible for up to 50% of colds). Other cold causing viruses are:
- Human parainfluenza virus
- Human respiratory syncytial virus
The body can never build up resistance to all the possible viruses (over 200) that can cause it. That’s why colds are so common and you can get them more than once a year. According to the Centers for Disease Control and Prevention, younger children get more colds per year than adolescents and adults. The coldness of the weather doesn’t increase the risk of catching a cold or spreading one.
What causes the flu?
The flu (influenza) is caused by influenza virus types A, B, and C.
Type A and B viruses are responsible for most of the larger flu epidemics. Type C flu virus usually only causes milder respiratory symptoms. The flu vaccine can help protect you from type A and B flu viruses.
There are subtypes of the Type A flu virus based on the chemical structure of the virus. But the Type B flu virus isn’t divided into subtypes.
Type A flu viruses are found in many different animals whereas Influenza B viruses only circulate widely amongst humans.
What causes a cough?
Most coughs are caused by an upper respiratory tract infection (e.g. as a result of the flu, the common cold or laryngitis). Lower respiratory tract infections are less common. This is where the lungs are infected and/or the airways lower down from the throat (windpipe) (e.g. due to bronchitis and in rare cases, pneumonia).
Disclaimer: The statements made on this page have not been evaluated by the U.S. Food and Drug Administration (FDA). They are not intended to diagnose, cure or prevent any disease. If a condition persists, please contact your physician or healthcare provider. The information provided is not a substitute for a face-to-face consultation with a healthcare provider, and should not be construed as medical advice.