People with the flu often experience fever, chills, cough, sore throat, runny or stuffy nose, muscle or body aches, headaches and/or fatigue, according to the US Centers for Disease Control and Prevention. Some -- more commonly children -- may also have vomiting and/or diarrhea.
Especially in the winter months, it's easy to mix up cold and flu symptoms.
According to Dr. Rachael Lee, assistant professor in the University of Alabama-Birmingham's Division of Infectious Diseases, there are certain ways to tell the difference. "Colds are typically around your nose and face, and you have a sore throat," she said.
"Your symptoms are more gradual in onset, and you may have a low-grade fever but not high fevers. It can also cause cough but does not have shortness of breath."
As for the flu, "it is pretty much all of a sudden: You will have fevers, body aches, sore throat, coughs, and then you can have other symptoms as well, such as shortness of breath. You can feel dehydrated, meaning you may be dizzy, and you may be a little bit confused."
Those who are at higher risk for developing flu-related complications should take extra precautions when they feel symptoms coming on.
The CDC says these include children under 5 years old, particularly those under 2. Also at high risk are adults 65 and older, pregnant women, residents of long-term care facilities and people with medical conditions including weakened immune systems, asthma, heart disease and diabetes.
Individuals with minor flu or flu-like symptoms should refrain from going to the emergency room and instead call their primary health care providers, to avoid overstressing community resources.
Be prepared to wait
"For all patients, first and foremost, you should call your health care provider, because you may be able to get (the antiviral medication) Tamiflu, and the earlier you get Tamiflu, the more likely your symptoms will go away faster," Lee said. "Do not wait with your symptoms. It is OK to bug us, as health care providers, because we are here to help."
Those who do need to visit an emergency department, however, should be prepared for a long wait time.
"You should seek care in the emergency department when you are feeling dehydrated, you are not keeping any fluids down, as well as if you are feeling really short of breath and cannot catch your air," Lee said.
Dr. Bernard Camins, also an associate professor in the Division of Infectious Diseases, said flu prevention should be the focus for the public.
Prevention key to protection
The most important thing is prevention: avoiding anyone who is sick, if possible, Camins said.
"This includes avoiding public areas where they could get infected, staying away from family or friends who may be sick and not allowing sick individuals into their homes. They also need to practice proactive and frequent hand hygiene. Prevention is the key."
To protect yourself and your loved ones from getting the flu in the first place, the University of Alabama-Birmingham suggests that you get the flu vaccine if you are 6 months or older, cover your coughs and sneezes, and wash your hands frequently.
You should also clean your living and work areas, avoid crowds where possible, stay home from work or school if you are sick and avoid touching your eyes, nose and mouth.
According to Lee, the vast majority of people who "get rest and drink fluids and take Tamiflu ... will get over your symptoms pretty quickly."