Is It a Cold or an Allergy?
The human body is a marvellous machine, but it’s also vulnerable to different viruses and bugs. Some of these illnesses can cause confusion as their symptoms may be similar.
An allergy is caused by an abnormal reaction to a substance. This is not true for everyone, of course, but some of us have immune systems that overreact to certain substances, or allergens.
Types of allergies
You can be allergic to food, dust mites, certain types of weather conditions, medication, preservatives, insect bites and pollens.
How your body reacts
When your immune system detects an allergen, it produces antibodies, or sends white blood cells to the area to attack the intruder. This leads to a chain reaction in the cells, ultimately leading to the release of potent chemicals like histamines.
Symptoms of allergies
These include a runny nose, itchy skin, hives, sneezing, a stuffy nose, red or watery eyes, a postnasal drip or dark circles under the eyes.
Depending on your specific allergies, some preventive maintenance at home could help control the environment, reducing the risk of allergic reactions. Such preventative measures could include:
- Use special mattress and pillow covers to control dust mites.
- Vacuum and dust frequently to get rid of dust mites and other airborne allergens.
- Use an air conditioner in your home and car and change the filters often.
- Get rid of old bedding, toys, clothing and other items that may be dust and mould carriers.
- Keep pets outdoors as much as possible and off the furniture.
- Bathe your pets regularly to reduce dander.
- Mop uncarpeted surfaces regularly.
- Remove overstuffed furniture and carpets to reduce dust mites.
A cold is caused by a virus. There are many viruses that can cause a cold.
If you have a cold, you’re usually contagious from 24 hours before symptoms start and as long as they last, which is usually about a week.
Viruses are most often spread by direct contact with infected secretions, e.g. touching objects such as handkerchiefs, doorknobs or eating utensils that a person with a cold has touched before, and then touching one’s nose or mouth.
How your body reacts
Your immune system responds by attacking the virus with white blood cells.
If your immune system cannot recognise the virus from a previous infection, the response is “non-specific”, meaning your body produces as many white blood cells as possible and circulates them to the infected sites. White cells produce chemicals to kill virus-infected cells, and this is what causes the nasal inflammation and swelling, increased mucous secretions and the general feeling of achiness.
Once infected with a specific cold virus, the body develops immunity to it in the form of “memory white cells” and antibodies, which will control the virus quickly in the event that it is encountered again. Immunity will prevent another cold being caused by the same rhinovirus for some months at least but does not protect against others.
Symptoms of colds
Sneezing and nasal congestion, a sore throat and a cough are typical of a cold. You may also have a runny nose, headache, sore throat, cough and tiredness.
There’s no sure way to prevent colds, especially in children. You can try to stay as healthy as possible though, including:
- Wash your hands often, especially when you are around people with colds.
- Stop smoking. Smoking irritates the mucous membranes of the nose, sinuses, and lungs, which may make them more susceptible to infections.
- Keep your stress levels under control. If you are exposed to cold viruses, a high level of stress may increase your chances of catching a cold.
- When you have a cold, avoid sneezing without covering your mouth. Also avoid spreading nasal secretions on your hands. Use disposable tissues rather than a handkerchief.