{"id":5673,"date":"2019-09-03T13:07:57","date_gmt":"2019-09-03T17:07:57","guid":{"rendered":"https:\/\/www.singlecare.com\/blog\/?p=5673"},"modified":"2020-10-05T14:19:44","modified_gmt":"2020-10-05T18:19:44","slug":"what-is-the-flu","status":"publish","type":"post","link":"https:\/\/www.singlecare.com\/blog\/what-is-the-flu\/","title":{"rendered":"What is the flu?"},"content":{"rendered":"

What is the flu?<\/a> | Symptoms<\/a> | Complications<\/a> | How long does it last?<\/a> | Transmission<\/a> | Treatment<\/a> | Prevention<\/a> | Reinfection<\/a><\/span><\/p>\n

Each fall, while stocking up on back-to-school supplies, raking leaves, and indulging in pumpkin spice, many American families start thinking about the flu\u2014and how to avoid it. And this year, that\u2019s more likely true than ever as scientists have warned about a \u201ctwindemic\u201d with the typical flu season hitting at the same time as the COVID-19 pandemic.<\/span><\/p>\n

In a normal year, up to 20% of the population will get sick with the flu, according to the <\/span>Centers for Disease Control and Prevention<\/span><\/a> (CDC). Peak flu season is December through February, but some years it can last until May.\u00a0<\/span><\/p>\n

Just because it\u2019s on your radar doesn\u2019t mean you know how the virus spreads or how to manage it. For that, it helps to understand why it comes back each year, the different strains, and how to deal with symptoms.<\/span><\/p>\n

What is the flu?<\/b><\/h2>\n

The influenza virus, commonly called the flu, is \u201ca seasonal infectious disease that can affect the throat, nose, and sometimes lungs and which results in fever, body aches\/chills, and overall fatigue,\u201d says <\/span>Saba Hamiduzzaman<\/span><\/a>, MD, an internal medicine physician and a pulmonologist at\u00a0Loma Linda University Health. It is a contagious respiratory tract infection that can cause mild to severe illness and, in some cases, death.<\/span><\/p>\n

Types of flu viruses<\/b><\/h3>\n

Although we refer to this seasonal sickness as <\/span>the<\/span><\/i> flu, there are actually <\/span>four types<\/span><\/a>: A, B, C, and D influenza viruses.\u00a0<\/span><\/p>\n

It\u2019s only \u201cthe influenza A and B viruses that routinely spread in people that are responsible for seasonal flu epidemics each year,\u201d says Dr. Hamiduzzaman.<\/span><\/p>\n

Influenza A viruses <\/b>are further divided into subtypes based on two proteins on the surface of the virus: hemagglutinin (H) and neuraminidase (N). While many different H and N subtypes have been identified, only a few routinely circulate in humans\u2014including H1N1 and H3N2. The well-known Avian flu, spread among aquatic birds, and <\/span>swine flu<\/span><\/a>, spread among pigs, also fall in this category. These types of new and different influenza A viruses can cause an influenza pandemic if able to successfully infect humans.\u00a0<\/span><\/p>\n

Influenza B viruses<\/b> are not divided into subtypes like A, but circulate in lineages and strains. Today, influenza B viruses belong to one of two lineages: B\/Yamagata and B\/Victoria.<\/span><\/p>\n

Influenza type C viruses<\/b> generally cause only mild respiratory illness.\u00a0<\/span><\/p>\n

Influenza D<\/b> viruses<\/b> mostly affect cattle.<\/span><\/p>\n

Flu misnomers<\/b><\/h3>\n

There are other so-called flus that, name aside, have nothing to do with the influenza virus.\u00a0<\/span><\/p>\n

This includes <\/span>stomach flu<\/b>, medically known as viral gastroenteritis, an intestinal disease that can last from a couple days to as many as 10. You can contract it from an infected person or contaminated food or water. Symptoms include watery diarrhea, abdominal cramps, nausea or vomiting, and sometimes fever.<\/span><\/p>\n

Keto flu<\/b> is another faux-influenza. This occurs in people following the keto diet\u2014eating minimal sugars and starches in favor of healthy fats and protein. The body burns fat for fuel in the absence of the glucose that carbohydrates provide. The result is symptoms similar to influenza, including nausea, weakness or fatigue, stomach cramps, dizziness and poor concentration. These symptoms typically last a week.<\/span><\/p>\n

Then there is <\/span>brain flu<\/b>. In this case, a brain infection causes encephalitis, which can present as mild flu-like symptoms such as headache, fever, and muscle soreness. It requires medical care by a doctor or healthcare provider.<\/span><\/p>\n

What are the symptoms of the flu?<\/b><\/h2>\n

The first sign of the flu can be extreme fatigue. People may feel so tired that daily activities become a challenge. Body aches and chills are common symptoms as the flu sets in, along with a persistent cough and sore throat.<\/span><\/p>\n

\"Cold<\/p>\n

A cold vs. the flu<\/b><\/h3>\n

Many people have a hard time differentiating between flu symptoms and a bad cold. \u201cThe symptoms of a cold are milder and usually associated with a runny or stuffy nose and sore throat,\u201d Dr. Hamiduzzaman explains.\u00a0\u201cPatients with the flu will feel very run down and symptoms will be more pronounced than with the cold.\u201d<\/span><\/p>\n

Cold symptoms typically have a gradual onset and may include:<\/span><\/p>\n