Flu Symptoms: What You Might Feel

Wonder if you have flu? While flu symptoms often mimic a cold, a common cold rarely causes a fever over 101 degrees Fahrenheit. Let's learn more about flu symptoms, so you are fully prepared if you get sick this flu season.

Why do I need to know about flu symptoms?

Flu is an acute respiratory infection caused by a variety of flu viruses. It's important to understand flu symptoms so you can seek immediate medical treatment, especially if you have a chronic medical condition.

The earlier you recognize you have flu can also make a difference in how long it lasts. Newer prescription medications called antiviral drugs -- zanamivir (Relenza) and oseltamivir (Tamiflu) -- are most effective when given within 48 hours of the onset of flu symptoms. These flu drugs can decrease the duration of the flu by 1 day if used within this early window. These antivirals are usually given for a period of about 5 to 7 days.

How will I know flu season has started?

A good sign that flu season has started is the sudden increase in the number of school-aged children sick at home with flu-like illness. This initial flu outbreak is soon followed by similar infection in other age groups, especially adults.

How are flu symptoms different from symptoms with colds?

Unlike symptoms of a common cold, flu symptoms usually come on suddenly. The flu usually starts with the abrupt onset of fever, headache, fatigue, and body aches. Here's a list of flu symptoms you might feel:

• fever (usually high)
• severe aches and pains in the joints and muscles and around the eyes
• generalized weakness
• ill appearance with warm, flushed skin and red, watery eyes
• headache
• dry cough
• sore throat and watery discharge from your nose

For more information, see WebMD's Flu Symptoms or Cold?

What are common flu symptoms in children?

Classic flu symptoms in children include high-grade fever up to 104 degrees F (40 degrees C), chills, muscle aches, headaches, sore throat, dry cough, and just plain feeling sick. These flu symptoms usually last for 3 to 4 days, but cough and tiredness may linger for up to 2 weeks after the fever has gone away. Other family members or close contacts often have a similar illness.

For in-depth information, see WebMD's Children and Flu.

What about flu symptoms in infants and toddlers?

In young children, flu symptoms may be similar to other respiratory tract infections such as croup, bronchitis, or pneumonia. Abdominal pain, vomiting, and diarrhea are frequently observed in young children. Vomiting tends to be more significant than diarrhea. Fever is usually high and irritability may be prominent.

In infants, flu symptoms often go unrecognized because the flu signs and symptoms are not specific and may suggest a bacterial infection. Flu in infants younger than 6 months is less common, but symptoms include lethargy, poor feeding, and poor circulation.

Because young children are at increased risk of getting severe flu complications, the CDC recommends that all children aged 6 months up to 5 years get a flu vaccine every fall or winter.

For in-depth information, see WebMD's Children and Flu.

Are there complications with flu symptoms?

According to the CDC, complications of flu can include bacterial pneumonia, ear infections, sinus infections, dehydration, and worsening of chronic medical conditions such as congestive heart failure, asthma, or diabetes.

For in-depth information, see WebMD's Flu Complications.