Are you SURE you have the flu? Or is it just a common cold? Experts explain the red flags to look out for

The common cold and the flu both share symptoms of a sore throat, coughing, congestion and sneezing

However if your symptoms come on fast and hard, it means you have the flu

Doctors warn that infants and adults should see a doctor within 24 hours if they have a high-fever, chills and body aches

If you begin experiencing dizziness and chest pain it could be a sign the flu has turned into something deadly, doctors told Daily Mail Online

The common cold and flu share multiple symptoms that can make it nearly impossible to identify which one you're suffering from until it is too late.

Sneezing, coughing and congestion can be either illness, but having a fever and body aches come on fast and strong are tell-tale signs that you have the flu.

While one can cause a few days of discomfort, the other can lead to potentially fatal complications that have so far killed 85 adults and more than 30 children across the US this flu-season.

Speaking to Daily Mail Online, two internists broke down each viruses' unique symptoms and when to know it's time for medical help because 'if you miss it, it can kill you.'

Fever, chills and body aches are red flags that you have the flu and not just the common cold, according to medical professionals 

Shared symptoms of both the flu and a cold are sneezing, congestion, a cough and sore throat.

'Oftentimes in their earliest stages it can be difficult to differentiate between these conditions,' said Dr Brian Secemsky, an internist at One Medical in San Francisco.

Symptoms unique to the flu include a high-grade fever, chills, body aches and nausea.

Cold symptoms usually stay in the nose, throat, ears and chest area.  

Florida-based internist Dr Gail Van Diepen said that a fever is typically the biggest red flag that you have the flu.

The quick onset of symptoms can also help distinguish between the two.

Most people experience cold-like symptoms for a few days before reaching the peak of the illness. 

Influenza comes on hard and fast.

'It can be as instantaneous as one minute you're fine and the next minute you have a headache and you begin to have cold sweats,' according to Dr Van Diepen.

Dr Secemsky urges people to see a doctor if you begin to experience dizziness, shortness of breath or chest pain as it is a sign that flu symptoms may have developed into pneumonia or infection.

'Mothers should take babies to see a doctor within 24 hours if they have a high fever,' said Dr Van Diepen.  

She warned that elderly people and those with pre-existing medical conditions, such as diabetes and lung disease, should especially seek medical help because they are more prone to serious infection.  

Smokers are also more susceptible to developing pneumonia from the flu so it is vital for them to seek medical help at the onset of symptoms. 

'Vomiting can lead to dehydration so that would also raise concern to see a doctor with a day,' she said. 

While hospitals across the US are overcrowded and understaffed, Dr Van Diepen said you should still get on line. 

'Don't wait too long to see a doctor and if your doctor can't see you go to a walk in clinic,' she said. 'Be proactive and don't assume it's just a cold and lay around for a few days because you could end up with pneumonia.'

The common cold and the flu are both upper respiratory infections that are highly contagious and transmitted by coming into close contact with an infected person.

They can be passed through sneezes, coughs and touching surfaces that carry the bacteria. 

'While the majority of patients who get flu symptoms do quite well taking care of themselves at home, one should consider seeing a primary care clinician if he/she is of advanced age and has serious chronic health conditions,' Dr Secemsky said.

Over-the-counter medications can help ease the symptoms of both a cold and the flu and antiviral drugs are most effective if taken within 48 hours of the onset of symptoms.  

THE MYTHS AND FACTS ABOUT THE FLU SHOT

It is a myth that the flu shot can give you the flu.

'There isn't any live virus in the influenza vaccine so it's impossible to get the flu from the vaccine,' said Dr Tosh from the Mayo Clinic.

'There was a live vaccine that's not available any more, but it was impossible to get the flu from that too,' he added.

CDC officials insist it is not too late to get the flu shot, despite evidence that this year's vaccine is only 30 percent effective against H3N2.

The H3N2 strain of the virus has so far killed 85 adults and 20 children in the US. 

Health officials say that the vaccine could be even more valuable now since it is more effective against strains which are only just emerging - including the H1N1 strain and various B viruses.

CDC figures show the majority of Americans do not get the flu shot and more and more parents are refusing to vaccinate their children.

New stats released on Friday show the rate of hospitalizations is soaring, not dipping, as the CDC had hoped

The CDC urges everyone to get their flu shot to best protect themselves from the virus and say it is not too late.

'Getting the flu shot can help prevent the flu and reduce the intensity of the illness if one comes down with it - highly recommended to anyone without a contraindication to receive it!' said Dr Secemsky. 

Though health officials strongly encourage getting vaccinated, more parents are refusing to immunize their children.

While vaccination rates are up 12 percent since 2013, vaccine refusals are also up to more than four percent, according to the Blue Cross Blue Shield Association.

The flu shot is 30 percent effective against preventing the most common strain of the virus, H3N2, that is dubbed the 'Aussie flu' and responsible for the devastating 2014 flu season. 

However, the shot is more effective in preventing B strains and the H1N1 virus that are just beginning to emerge.

'Supporting one's immune system with good rest and adequate hydration may help reduce the severity of symptoms,' said Dr Secemsky. 

'Washing hands often, wearing masks, and staying home from work during periods of fever can help reduce the transmission of the virus,' he added. 

Doctors said that you should seek medical help within 24 hours if you have a fever and chills, especially for infants and elderly people