How can you tell if it is a cold or flu?

Answer 1

The same way as between a cold and regular flu. With a cold you'll just have the standard sore throat, cough, runny nose, possibly slight fever. If you're getting into throwing up/diarrhea/temperature over 100 degrees, that's when you are beyond the cold.

It's also worth noting that flu is mainly characterised by symptoms like dizziness, high fever (as noted above) diarrhea and vomiting, muscle aches, shortness of breath and lung restriction (finding it painful to take a full breath) and headaches. Your common cold symptoms are likely to occur alongside any of the above symptoms. (Common cold symptoms include sneezing, sore throats, runny noses, irritable cough, congested sinuses, etc)

Answer 2

Most local medical laboratories in the US now can do preliminary testing for Influenza Type A and Type B. Based on the types of flu that doctors and hospitals are seeing in your area at that time, they can usually determine from the Type A or B which kind of flu you have and the treatment is basically the same, anyway. From there, however, if they need more specific information of exactly which subtype or strain of virus, in most cases, there would need to be testing at an outside esoteric laboratory or at the CDC laboratory.

The only way to be absolutely sure it is the 2009 Swine Flu (A-H1N1/09) is laboratory testing. If testing beyond use of a field test kit sample from a nasal swab is advised by your care provider, the CDC describes the appropriate tests as:

"... a respiratory specimen would generally need to be collected within the first 4 to 5 days of illness (when an infected person is most likely to be shedding virus). However, some persons, especially children, may shed virus for 10 days or longer. Identification as a swine flu influenza A virus requires sending the specimen to CDC for laboratory testing."
The only way to be sure it is the 2009 Swine flu (A-H1N1/09) is laboratory testing. If testing is advised by your care provider, there are now "field test kits" that the CDC has provided regionally for providers and labs to be able to do preliminary testing to detect the presence of Novel A-H1N1/09 cases.

However, to do the most sensitive and reliable testing, the CDC describes the appropriate tests as:

"... a respiratory specimen would generally need to be collected within the first 4 to 5 days of illness (when an infected person is most likely to be shedding virus). However, some persons, especially children, may shed virus for 10 days or longer. Identification as a swine flu influenza A virus requires sending the specimen to CDC for laboratory testing."

More recently, testing is available through other approved laboratories and not solely from the CDC labs.

Answer 3

Influenza, or flu, is a respiratory disease, primarily. The main difference between it and a cold is that the flu usually causes uncomfortable body aches along with a fever. See also the related question below.

Answer 4

The main difference seems to be that after about 5 days the symptoms can beome worse and progress to severe conditions such as pneumonia