If you're confused, that's because sometimes the terms ARE inter-changeable.
Technically, influenza and colds are caused by two different and distinct families of viruses.
Typically, flu is much worse than a cold virus. It's distinctive difference from a mere cold is fever; you may feel awful with a cold, but you don't usually run a fever, certainly not a high one. Cold symptoms last up to 3 weeks, flu usually lasts longer. Flu is rather rare.
Cold or flu viruses can cause a viral chest infection.
A chest infection is an umbrella term for viral or bacterial infection in the respiratory tract. The worst type of chest infection, is pneumonia -- but not all chest infections turn into pneumonia.
Pneumonia is a very serious chest infection, that typically includes inflammation and fluid in the lungs.
So you may catch a cold or flu, that later turns into pneumonia. Also, there are other plenty of microbes, bacteria especially, that can lead to cold-like symptoms or even pneumonia. And while you're suffering from one bug, another nasty microbe may take advantage of your weakened immune system (from fighting the mere cold) to get settled in the lungs and cause a more serious illness.
Technically, influenza and colds are caused by two different and distinct families of viruses.
Typically, flu is much worse than a cold virus. It's distinctive difference from a mere cold is fever; you may feel awful with a cold, but you don't usually run a fever, certainly not a high one. Cold symptoms last up to 3 weeks, flu usually lasts longer. Flu is rather rare.
Cold or flu viruses can cause a viral chest infection.
A chest infection is an umbrella term for viral or bacterial infection in the respiratory tract. The worst type of chest infection, is pneumonia -- but not all chest infections turn into pneumonia.
Pneumonia is a very serious chest infection, that typically includes inflammation and fluid in the lungs.
So you may catch a cold or flu, that later turns into pneumonia. Also, there are other plenty of microbes, bacteria especially, that can lead to cold-like symptoms or even pneumonia. And while you're suffering from one bug, another nasty microbe may take advantage of your weakened immune system (from fighting the mere cold) to get settled in the lungs and cause a more serious illness.