Colds can occur year round but are most common in winter. Symptoms generally include a runny nose, nasal congestion and sneezing, but you may also have a sore throat, cough, headache and mild fever. When someone is down with a cold, his or her nose is teeming with cold viruses and sneezing, nose blowing and nose wiping all spread the virus. You can catch a cold by sitting close to someone with a cold and inhaling the virus or by touching your eyes, nose and mouth after you have touched something contaminated with the virus. People are typically most contagious for the first three days of the cold and not contagious at all after a week.
Once you have caught a cold, symptoms appear within a few days and typically begin with a scratchy throat, followed by sneezing and watery nasal secretions that gradually turn thicker, becoming yellow and green. Most colds are over in a week, with perhaps a few symptoms – such as a cough – lingering on for a further week.
If you get a cold you don’t need antibiotics to treat it unless you have yellow or green nasal discharge for more than 10–14 days. Over-the-counter remedies can offer relief but they won’t cure it. It’s important to rest and drink plenty of fluids.
Caused by the influenza virus which gives it its name, the ‘flu’ which typically arrives in the winter months is a contagious infection of the nose, throat and lungs. It often begins with a fever, raising your body temperature to 39–41ºC (about 102–106 ºF), and other common symptoms such as body aches, dizziness, lack of energy and a flushed face. The fever can last for up to five days but normally subsides after a day or two. Sometime around day four of the illness the ‘whole body’ symptoms subside and respiratory symptoms, such as coughs, sore throats, runny or blocked noses and sneezing, take centre stage. These symptoms tend to continue for about a week, but coughs and tiredness can linger for weeks after the rest of the illness is over.
The influenza virus is airborne and can be caught by breathing in droplets from coughs or sneezes. Most often, however, it is caught when you touch a tap, phone or door handle with the infection on it, and then touch your mouth, nose and eyes.
Millions of people get influenza every year; most recover but for some the symptoms are so severe that they need to be hospitalised. All ages are at risk of serious complications with flu, but those most at risk include babies, children, pregnant women, people over the age of 60, and anyone with diabetes or a chronic heart, lung or kidney condition.
In most people who are otherwise healthy, influenza subsides within seven to ten days. If you do get flu and are not in a high-risk category, resting, using over-the-counter medications that relieve symptoms, drinking plenty of water and avoiding alcohol, tobacco and antibiotics are the best ways to treat it. (For more advice on DIY methods to ease symptoms of colds and influenza, see ‘Part Three: Fighting Infection’.)
Most people get a cold several times a year but fortunately, influenza strikes only once every few years. The flu virus is often mistaken for a cold virus since both these infections share similar symptoms, but the two diseases are very different. For one thing colds tend to go away without causing trouble but influenza can lead to complications such as pneumonia. Being able to spot a case of flu quickly also opens up the possibility of taking antiviral medications, such as Tamiflu and Relenza, which can kill the virus and speed recovery. Once flu is diagnosed, your doctor can determine which one is best for you.
If you aren’t sure if you have a cold or a case of the flu, bear in mind that colds tend to come on gradually. The first sign is often a sore or scratchy throat, followed by a runny nose and sneezing. Other symptoms include coughing, headaches and stuffiness. Also colds don’t usually cause fevers in adults, although they can sometimes do so in children. The flu, on the other hand, leads quickly to a high fever and the symptoms tend to be far more severe. You might feel weak, tired and drained of all energy, and you might also experience chills, a sore throat, strong headaches and aches and pains (including eye pains).
Known as ‘avian influenza’, bird flu is a viral disease caused by different strains of the influenza virus. It mostly infects birds. Recent outbreaks in Europe have largely been caused by a highly contagious and virulent strain of the virus known as ‘H5N1’. At present, H5N1 is only mildly infectious to humans who have been in contact with infected birds and it cannot be transmitted from one human to another. However, virus experts fear that the H5N1 virus could mutate and be transferred to humans, or combine with other influenza viruses already infecting humans, causing a 21st-century flu pandemic on the scale of the ‘Spanish flu’ that followed World War I, which killed over 50 million people worldwide.
Research suggests that flu drugs, such as Relenza and Tamiflu, are effective treatments for the disease, although there is concern that such drugs may not be as readily available or as effective as hoped if the virus mutates. In addition, a number of companies are trying to develop a vaccine, although this is proving difficult as the flu virus mutates frequently and the vaccines need to be constantly modified.
Despite growing concern, health experts strongly advise the public not to panic as there is no immediate threat to humans. The World Health Organisation (WHO) has effective disease-control measures in place in areas where outbreaks have occurred or are likely to occur. Currently, the WHO is also creating an emergency plan to handle a pandemic and governments are stockpiling antiviral medications. The best way to protect yourself is to keep your immune system as strong as possible by following the guidelines in this book and by staying away from infected birds.
A weakened immune system will not only increase your susceptibility to colds and flu, it can also increase your risk of auto-immune disorders in which the immune system attacks healthy body cells.
Normally the immune system is capable of telling the difference between ‘self’ and ‘non-self’ tissue, but auto-immune disorders occur when it can no longer differentiate between the two. Why this happens is still uncertain. Some experts believe that these disorders occur following infection by some kind of organism that looks similar to particular cells in the body, which are later mistaken for the organism and targeted for attack.
In many cases, auto-immune disorders cause the destruction of body tissue, resulting in the decreased functioning of an organ or tissue, or several organs or tissues. Examples of auto-immune disorders include:
Chronic fatigue syndrome: A condition of prolonged weariness and fatigue that is not relieved by rest or caused by other medical conditions. Experts aren’t sure what causes it but one theory is that it is caused by some sort of auto-immune response.
Diabetes (Type 1): A disease that occurs when the pancreas produces too little insulin to regulate blood sugar. Symptoms include increased thirst, weight loss, fatigue and increased urination.
Multiple sclerosis: An auto-immune disease that affects the central nervous system (brain and spinal cord). Symptoms include fatigue, tremors and weakness in one or more extremities.
Pernicious anaemia: Caused by the lack of a substance needed to absorb vitamin B12 from the gastrointestinal track. Symptoms include fatigue, unsteady gait and bleeding gums.
Rheumatoid