An influenza infection, commonly known as the flu, is an extremely contagious respiratory illness caused by influenza viruses. It appears most frequently in winter and early spring and attacks the body by spreading through the upper and/or lower respiratory tract.
Influenza viruses are divided into three categories: types A, B, and C. All three types can mutate or change into new strains, but type A influenza mutates most often. This means that you can never develop a permanent immunity to influenza even if you develop antibodies against a flu virus one year. Those antibodies are unlikely to protect you against a new strain of the flu virus the following year.
Type A mutations make up the majority of flu epidemics every few years. Type B is less common and generally occurs every three to five years. Type C causes infection but does not cause typical flu symptoms.
How Does an Influenza Infection Spread?
Influenza is spread from person to person through respiratory secretions and typically sweeps through large groups of people who work in close proximity, such as in daycare facilities, classrooms, college dormitories, and offices.
Influenza spreads when you inhale droplets in the air that contain the flu virus. This occurs when you make direct contact with respiratory secretions through sharing drinks or utensils, or handle items contaminated by an infected person.
In the latter case, flu virus on your skin can infect you when you touch or rub your eyes, nose or mouth. That’s why frequent and thorough handwashing is a key way to limit the spread of influenza. Flu symptoms start to develop from one to four days after infection with the virus.
Signs & Symptoms
Influenza is a contagious respiratory illness caused by flu viruses. It can cause mild to severe complications, and at times can lead to death. The flu is different from a cold; it usually comes on suddenly with some or all of these symptoms:
- Fever or feeling feverish/chills
- Cough
- Sore throat
- Runny or stuffy nose
- Muscle or body aches
- Headaches
- Fatigue (tiredness)
Some people may also have vomiting and diarrhea, though this is more common in children than adults.
Complications and Risks
Most people who get an influenza infection will recover in several days to less than two weeks, but some people will develop severe complications. Influenza infection of the upper respiratory tract (nasal passages, throat) and lower respiratory tract (lungs) can cause moderate complications (sinus and ear infections) to serious complications (pneumonia or inflammation of the heart, brain, or muscle tissue).
While anyone can get sick with flu and become severely ill, some people are more likely to experience severe flu illness. Young children, adults aged 65 years and older, pregnant women and people with certain chronic medical conditions are among those groups of people who are at high risk of serious flu complications.
Treatment and Relief
Influenza is treated primarily with rest and fluid to let the body fight the infection on its own. Over-the-counter anti-inflammatory pain relievers may help with symptoms. An annual vaccine can help prevent influenza and limit its complications.
Individuals with influenza should:
- Stay at home
- Avoid contact with other people where possible
- Reduce activity for a short period to promote rest
- Keep warm and rested
- Consume plenty of liquids
- Avoid alcohol
- Stop smoking
- Eat if possible
Over-the-counter medications to soothe and reduce symptoms include throat lozenges, decongestants, pseudoephedrine (Sudafed, SudoGest, Wal-Phed, Suphedrine), cough medicine, and guaifenesin (Mucinex, Robitussin). Anti-inflammatory drugs (Advil, Motrin, Midol, NeoProfen) also help relieve pain, decrease inflammation and reduce fever.
Individuals that live alone should tell a relative, friend, or neighbor that they have influenza; and make sure someone can check in on them.
Schedule a Consultation
Influenza can leave you feeling under the weather. Recognizing and understanding the symptoms, causes and treatment options can ease side effects of an influenza infection. If you experience any flu symptoms, it may be time to discuss a treatment plan with your doctor. Join our many satisfied patients, and schedule an appointment with Dr. Shukla today.
