Infection of the throat, nose, and lungs is called influenza (also called flu). This condition is caused by a virus. However, the virus that causes “stomach flu” is different from this virus. People with “stomach flu” may experience vomiting and diarrhea.
In most cases, the flu goes away on its own and does not require treatment. However, the complications caused by influenza may be life-threatening. Healthcare providers recommend getting an annual flu shot that will help to protect you against seasonal flu. While this flu vaccine is not 100% effective it may reduce the risk of serious complications of influenza. Moreover, along with the vaccine, you can take some steps that also may prevent the infection. These include cleaning the air that surrounds you, disinfecting surfaces, and regularly washing your hands.
Symptoms
The viruses that cause the flu spread quite fast during certain periods of the year in the Northern and Southern hemispheres. For instance, in North America flu season begins in October and finishes in May.
The most common flu symptoms include sore throat and runny or stuffy nose. However, previous symptoms may also occur in people with colds. The difference between a cold and flu is that symptoms in a cold tend to begin more slowly but in people with flu symptoms appear more quickly. Check below for other influenza symptoms:
Sometimes, adults may experience eye pain, watery eyes, and sensitivity to light.
Children are more prone to develop influenza than adults and symptoms include ear pain, vomiting, diarrhea, and irritability.
Commonly, people get rid of this infection at home and do not need to see a doctor. Immediately contact a healthcare provider if you experience any of the following emergency symptoms of influenza. Examples include:
- Persistent dizziness
- Chest pressure or pain
- Breathing problems or shortness of breath
- Confusion
- Seizures
- Dehydration
- Worsening of other health problems
- Severe weakness
- Muscle pain
Check below also emergency symptoms of the flu in children:
- Worsening of the existing symptoms including fever or cough
- Cry without tears and dry mouth
- Blue or gray lips or nail beds
- Fast breathing
Causes
This infection of the respiratory system is caused by a virus that travels through the air when an infected person coughs, sneezes, or talks. People usually become infected while breathing droplets directly or when touching certain surfaces such as a computer keyboard.
The symptoms usually appear within 1 week after exposure to the virus. During this period you are contagious, which means you can infect other people. Those who have weakened immune systems and children are contagious a little longer. Furthermore, influenza continuously mutates which leads to the appearance of new strains.
Once you have had influenza, you get long-term protection against these strains of the flu. However, annual vaccines offer protection against flu strains that may occur this season.
Risk Factors
Anyone can get this infection and there are different risk factors that may put you at increased risk of getting influenza. Check some of them below:
- Age – Children before 2 years old and younger and older adults after 65 years old are more likely to develop influenza.
- Weakened immune system – People with a weakened immune system have an increased risk of getting the virus and its complications.
- Chronic health conditions – The risk of flu complications increases in people with diabetes, other lung conditions, heart disease, nervous system diseases, stroke, metabolic disorders, and those who have problems with the airways, kidneys, liver, or blood.
- Living conditions – Those who live in facilities with many residents are more prone to develop influenza.
- Aspirin therapy – Young people who follow long-term Aspirin therapy and get the flu virus may experience Reye’s syndrome.
- Pregnancy – Women during pregnancy have elevated risks of getting the influenza virus.
- Obesity – People high in weight also have an increased risk of getting this infection and its complications.
- Ethnicity and race – Native Americans or Alaska Natives, Black, or Latino are at higher risk of getting the flu virus in the United States.
What Are The Potential Complications of Influenza?
People who leave influenza untreated may experience some complications. One common complication in people with flu is another infection. For example sinus or ear infections, croup, lung infections, heart muscle infections, and sometimes central nervous system infections. Check below other complications:
- Acute respiratory distress syndrome
- Muscle damage (also called rhabdomyolysis) or muscle swelling (myositis)
- Toxic shock syndrome
- Worsening of existing health conditions (including kidney disease, asthma, and others)
If you suspect you experience complications of flu, immediately seek medical care.
Prevention
The CDC (Centers for Disease Control and Prevention) advises vaccination annually for people from 6 months of age and older and for those who do not have medical reasons to not get the vaccine. It helps to reduce the risks of:
- Death caused by flu
- Having serious health problems due to influenza and needing to stay in a hospital
- Protect unborn baby during pregnancy
The vaccine provides protection against 3 influenza viruses that researchers think to be the most common this flu season. The flu vaccine is available as a shot, jet injector, and nasal spray. Doctors recommend the flu shot be given to a muscle in the arm for older children and adults and thigh muscle for younger children. However, if you are an adult under 65 years old, you may get the vaccine using a jet injector. A special device that uses a high-pressure, narrow stream of fluid that goes through the skin is called a jet injector.
Nasal sprays can be used by people between 2 and 49 years old. The following groups can use the vaccine in nasal spray form. Examples include:
- Young people who administer Aspirin or a medicine that contains Salicylate
- Pregnant women
- Those who experience a severe allergic reaction to a flu vaccine previously
- People with weakened immune systems, who take antiviral medications for influenza, and with a cerebrospinal fluid leak
- Children between 2 and 4 years old diagnosed with wheezing or asthma
How to Reduce the Spreading of the Infection?
The following tips can help you prevent spreading the infection to other people. For example:
- Regularly wash your hands
- Do not touch the face, especially after getting in contact with foreign objects or surfaces
- Cover your face with your elbow when coughing or sneezing
- Disinfect surfaces
- Avoid crowds
You are no longer contagious if you are fever-free without medications for at least 24 hours.
Diagnosis
To diagnose this infection, doctors usually perform a physical examination and ask questions about symptoms and your medical history. Sometimes, doctors may perform some tests to determine if the virus can spread to other people. Check below tests used to confirm the condition:
- Molecular tests – These tests are also called polymerase chain reaction tests (PCR tests) and are used to identify the genetic material of the flu virus.
- Antigen tests – This test is done to check for viral proteins (antigens).
Previous tests also are used to diagnose other respiratory conditions (such as COVID-19). In addition, some people can experience both influenza and other respiratory infections at the same time.
Treatment
Physicians usually prescribe certain antiviral medications for people with severe infection and increased risk of complications caused by flu. These include Oseltamivir, Baloxavir, and Zanamivir. For people who stay in the hospital doctors may prescribe a Peramivir that is given intravenously (IV). These medicines help to reduce the symptoms and prevent complications.
However, antiviral medications can cause some adverse reactions. These include diarrhea, nausea, vomiting, trouble breathing, and others. For more details, talk with your healthcare professional.
Frequently Asked Questions
What are the primary flu symptoms?
- Fever
- Muscle aches and pains
- Cough
- Chills
- Headaches
If you experience any of the symptoms listed above or extreme tiredness, weakness, sneezing, chest discomfort, stuffy nose, and sore throat, do not hesitate to visit a doctor.
What are the most common complications caused by influenza?
These include:
- Sinus and ear infection
- Bacterial pneumonia
- Dehydration
This infection may also worsen existing health problems including diabetes, heart failure, or asthma.
What are foods that may worsen the flu?
The following foods should be avoided by people with influenza. For example:
- Dairy products (including milk, yogurt, and ice cream)
- Alcohol and caffeine
- Processed foods
- Greasy foods
- Foods that may scratch the throat (such as crusty breads, crackers, pretzels, and others)
- Products high in sugar (such as candies, sweetened beverages, fruit juices, and others)
If you have additional questions, ask your healthcare providers.
