A 2007 Decima Research poll found that 79 per cent of Canadians surveyed reported going to work sick at some point in the past year. (CBC)Been feeling a little under the weather lately? Perhaps something's been percolating for a few days.

Chances are, you can probably breathe easier. You probably don't have the flu. One of the major differences between a cold and the flu is that the flu can develop suddenly — you feel very sick within a few hours. A cold usually develops over the course of a few days.

Sneezing is not normally associated with the flu. Coughing accompanies both colds and the flu. With a cold, it's usually a hacking cough. With the flu, it can be severe.

Fever is another common symptom of the flu. Your temperature can remain above 38.5 C for two to four days. You don't have a fever when you have a cold.

Other common flu symptoms include:

• Fatigue.
• Muscle aches.
• Sore throat.
• Headache.
• Chills.
• Decreased appetite.
• Runny or stuffy nose.

Other symptoms you may encounter include:

• Nausea.
• Vomiting.
• Diarrhea.

The vast majority of swine flu cases have been "mild" — however, even a mild case of the flu can make you feel pretty awful for a week or more. The flu can leave you feeling that even reading a book is more work than you can handle.

It can take two to three weeks for your energy levels to return to normal after a bout of the flu.

Rest is the best way to treat your flu — unless your case becomes serious. If you develop any of the "emergency warning signs," you will need to get medical care immediately.

In children, those signs include:

• Fast breathing or trouble breathing.
• Bluish skin color.
• Not drinking enough fluids.
• Not waking up or not interacting.
• Being so irritable that the child does not want to be held.
• Flu-like symptoms improve but then return with fever and worse cough.
• Fever with a rash.

In adults, emergency signs include:

• Difficulty breathing or shortness of breath.
• Pain or pressure in the chest or abdomen.
• Sudden dizziness.
• Confusion.
• Severe or persistent vomiting.

In Canada, 1,600 people were admitted to hospital suffering from swine flu between April and October. Approximately 300 of them wound up in the intensive care unit. So far, there have been about 115 deaths across Canada, including six children.

The vast majority of severe cases have been in people with one or more medical conditions that place people at high risk of serious seasonal flu-related complications. Those conditions include pregnancy, diabetes, heart disease, asthma and kidney disease. Your flu symptoms won't develop for two to seven days after you've been infected. You can infect others a day before you start to show symptoms until about seven days after your symptoms have developed.

The best way to reduce your risk of infection is through frequent handwashing.