Influenza (or flu) is a highly contagious viral respiratory tract infection. An estimated 5 to 20 percent of people nationwide contract influenza each year. Influenza is characterized by the fast onset of fever, muscle aches, sore throat and a nonproductive cough. Influenza can make people of any age ill. Although most people are ill with influenza for only a few days, some have a much more serious illness and may need to be hospitalized. Although the flu usually is mild in children and younger adults, it can cause life-threatening viral pneumonia in older adults.
The influenza virus is generally passed from person to person by airborne transmission (i.e., sneezing or coughing). The virus also can live for a short time on objects, such as doorknobs, pens, pencils, keyboards, telephone receivers, and eating or drinking utensils. Therefore, it also may be spread by touching something that has been handled by someone infected with the virus and then touching your own mouth, nose or eyes. Being aware of your surroundings and taking precautions can help prevent influenza.
Influenza and the common cold often are confused. If you’ve been exposed to others with the flu virus and you suddenly feel feverish and achy all over, it’s probably the flu. Flu symptoms often come on so fast, people can tell you the hour they got sick. You may have mild cold-like symptoms, but mostly your head and muscles ache, and you shake with chills and burn with fever. Children may have nausea and vomiting as well, says pediatrician Michael Consuelos, MD, of Lehigh Valley Health Network.
The following are the most common symptoms of the flu. However, each individual may experience symptoms differently. Influenza is called a respiratory disease, but the whole body seems to suffer when you are infected. People usually become acutely ill with several, or all, of the following symptoms:
- High fever
- Runny or stuffy nose
- Sneezing at times
- Cough, often becoming severe
- Severe aches and pains
- Fatigue for several weeks
- Sometimes a sore throat
- Extreme exhaustion
Fever and body aches usually last for three to five days, but cough and fatigue may last for two weeks or more. Although nausea, vomiting and diarrhea may accompany the flu, these gastrointestinal symptoms are rarely prominent. "Stomach flu" is an incorrect term sometimes used to describe gastrointestinal illnesses caused by other microorganisms.
If your child has flu-like symptoms, is lethargic and won’t drink fluids, call your doctor right away. Also seek medical care if you suspect strep, a bacterial infection that can be serious. A streptococcus infection also can cause fever and nausea. With strep, the patient will have an extremely sore throat and swollen glands just under the jaw.
If you have chronic heart or lung disease, asthma, diabetes, HIV or kidney dysfunction, or if you’re pregnant or over age 65, you’re at higher risk for complications and should see your doctor at the first sign of flu symptoms.
The symptoms of the flu may resemble other medical conditions. Always consult your doctor for a diagnosis.
“See your physician promptly if you think you have the flu,” says family medicine physician David Zambo, DO, of Lehigh Valley Health Network. The goal of treatment for influenza is to help prevent or decrease the severity of symptoms. Treatment may include:
Medications to relieve aches and fever
For a fever higher than 100 degrees, acetaminophen can relieve muscle aches and chills. Let a fever below 100 degrees run its course.
Drinking lots of fluids
When you’re dehydrated, everything hurts more. Water, sports drinks or anything you can keep down will help you feel better and reduce your fever.
You can loosen congestion with steam from a hot shower, vaporizer or pot of boiling water, or try a decongestant. To open a blocked nose, use warm water or saline nose drops.
Soup and cough medicine
You can ease a sore throat and cough with chicken broth, cough drops and cough medicine.
The flu is very contagious. Symptoms can occur 24-36 hours after first contact with an infected person.
When started within the first two days of treatment, antiviral medications can reduce the duration of the disease but cannot cure it. Four medications have been approved and include amantadine, rimantadine, zanamivir and oseltamivir. Some side effects may result from taking these medications, such as nervousness, lightheadedness or nausea. Individuals with asthma or chronic obstructive pulmonary disease are cautioned about using zanamivir. Viral resistance to these drugs may vary. Some drugs may be ineffective if current viral strains have developed resistance. All of these medications must be prescribed by a doctor.
- Specific treatment for influenza will be determined by your doctor based on:
- Your age, overall health and medical history
- Extent and type of influenza, and severity of symptoms
- Your tolerance for specific medications, procedures or therapies
- Expectations for the course of the disease
- Your opinion or preference
“If your fever persists more than two or three days or if you have an irregular heartbeat, wheezy cough, difficulty breathing or keeping food down, or severe confusion, call your doctor,” says family medicine doctor Dale Weisman, M.D., of Lehigh Valley Health Network. “These are signs of complications.”
The best way to prevent complications is to prevent the flu. Get vaccinated every fall, especially if you are at high risk. A new nasal spray vaccine is also available. You can further protect yourself by avoiding people with the flu and washing your hands regularly.
Extracorporeal membrane oxygenation (ECMO)
Extracorporeal membrane oxygenation (ECMO) helps patients who have a serious condition that affects their heart and/or lungs. With ECMO, blood is drawn from the body through a plastic tube, run through a machine that removes carbon dioxide and adds oxygen, and returned to the body. The patient remains on a low-level ventilator to keep the lungs moving, but because the heart and lungs are not working as hard, ECMO gives them a chance to heal.
Follow-up Care for Flu Patients
It’s not uncommon to have a dry cough and fatigue for several weeks after a bout of flu. But if you’ve been getting better and suddenly feel worse, with fever and rapid breathing or pulse, or pain when you move your eyes, call the doctor. This is especially important for children under age 2, adults over 65, or people with conditions like asthma, heart or lung disease, diabetes or immune disorders. If necessary, your doctor will prescribe antibiotics — but only if necessary.