What is the flu?

The flu (influenza) is a seasonal virus that can lead to symptoms ranging from mild to severe. It’s a respiratory illness that infects the nose, throat, and sometimes the lungs. Some recover in about a week, while others may be affected for much longer. In severe cases, it can lead to death.
The risk of life-threatening flu complications increases for those over the age of 65. As part of the aging process, the immune system can weaken over time. This makes it harder to fight off a flu virus.
Symptoms of a flu typically last for around five to seven days. For some older adults, particularly those with high risk factors, the flu may last one to two weeks. Some have reported experiencing cough and fatigue for up to three weeks.
When a flu infection becomes severe, it can lead to pneumonia, bronchitis, or heart failure. This may require hospitalization and can even result in death. It’s estimated that between 70 and 80% of seasonal flu-related deaths have occurred in people 65 years of age and older. Around 50 to 70% of the flu-related hospitalizations are also people in this age group.
While the flu is preventable through vaccines and other treatments, doctors often miss the flu in older adults. Older adults may show different symptoms or may not be tested for the flu, even if they are hospitalized. A clinical investigation found that influenza is underdiagnosed among older adults who are hospitalized.
Knowing the signs of the flu in seniors can help prevent severe complications and ensure that you get the help you need.
Symptoms of the flu
While symptoms of the flu can vary in severity, the symptoms tend to be consistent. The standard symptoms can include:
Many older adults who get the flu develop these typical symptoms. However, it’s also common for seniors to not experience a fever, cough, or sore throat. In fact, 26% of older adults hospitalized for the flu didn’t experience standard flu-like symptoms. They may instead experience some of the following symptoms:
Weakness
Older adults with the flu may instead experience a feeling of weakness, including difficulty balancing or walking. They may also experience a dizzy or light-headed feeling while standing up.
Loss of appetite
The flu may also lead to issues with digestion. This can include loss of appetite, feelings of nausea, or diarrhea.
Confusion
Older adults with the flu may experience mental confusion or delirium. This can look like difficulty focusing, memory problems, language problems, disorientation, or even hallucination. These symptoms can fluctuate, with the person alternating between clarity and confusion.
Worsening of chronic conditions
The flu may react differently in seniors by worsening chronic conditions like pulmonary disease, heart conditions, or asthma. A worsening of chronic obstructive pulmonary disease or asthma might look like shortness of breath or wheezing. Worsening heart failure symptoms might look like shortness of breath and/or swelling of the legs.

SLIDESHOW
How to Get Rid of a Cold: Natural Remedies See SlideshowCauses of the flu
The flu virus travels through the air through droplets, usually when someone breaths, talks, sneezes, or coughs. These droplets may be inhaled directly, or they may land on objects -- like a door handle or a telephone -- and be transferred to the eyes, nose, or mouth.
People who have the virus will be contagious for about five to seven days, while children and people with weakened immune systems may be contagious for longer.
Some factors may increase your risk of getting the flu or developing flu complications:
When to see the doctor for the flu
More serious symptoms may develop after flu symptoms in seniors have improved. Call your doctor immediately if you have any of these symptoms:
- Worsening or consistent symptoms after three to four days
- Difficulty breathing
- High fever
- Nausea and vomiting
- Shaking chills
- Severe muscle pain
- Chest pain
- Coughing with thick mucus
- Confusion
Diagnosis for the flu
To diagnose the flu, health care providers may examine your medical history and ask for more information about your symptoms. The test requires a swab of the inside of the nose or the back of the throat to test for the flu virus. Depending on the test, it can take 15 minutes or up to several hours to receive results.
Treatment for the flu
The CDC recommends the flu vaccine as the best protection against the flu, especially for higher-risk populations. While the flu vaccine isn't 100% effective, it can reduce the risk of catching the flu by 40% to 60%. One study found that, despite being at a higher risk for developing flu complications, the vaccine was equally effective at preventing the flu for older adults as it was for younger adults.
Mild cases of the flu can be treated with over-the-counter medications, as well as plenty of rest and fluids.
For older adults and/or those with chronic conditions or other risk factors, your healthcare provider may prescribe an antiviral drug like oseltamivir.
These medications can keep the flu virus from multiplying in your body. They can also reduce symptoms, encourage faster recovery, and lower the risk of more serious health problems. Antiviral drugs are most successful when given within 48 hours of a person developing symptoms of the flu.
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John Hopkins Medicine: "Influenza"
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