Flu

The flu, or influenza, is a respiratory illness caused by influenza viruses. It is distinct from the common cold and COVID-19, although some symptoms may overlap. The flu spreads from person to person through the air or by touching surfaces contaminated with the virus. While flu symptoms can be similar to those of the common cold, they are generally more intense and long-lasting. The flu can occur year-round but is most common during the fall and winter. Typically, flu cases rise in October and peak between December and February, with a second possible peak occurring as late as March or April. The timing of the flu season may vary each year, depending on factors such as circulating virus strains and vaccine effectiveness.

Causes

The flu is caused by influenza viruses that spread primarily through the air. These viruses can also be transferred by direct contact with contaminated surfaces. Once inside the body, they may lead to illness. Certain groups are at higher risk for severe flu complications, including:

• Pregnant women

• Children under 5 years old

• Adults 65 years and older

• Individuals with extreme obesity (BMI of 40 or higher)

• People with chronic illnesses

• Those experiencing homelessness

• Children and teenagers on long-term medications

• People with weakened immune systems

• Individuals who have had a stroke

• Residents in nursing homes or long-term care facilities

• Specific racial and ethnic groups, including Non-Hispanic Black, Hispanic, Latino, American Indian, and Alaska Native populations

Symptoms

Flu symptoms often appear suddenly and are typically more severe than cold symptoms. Common signs of the flu include:

• Fever lasting about 3 to 4 days

• Severe body aches

• Chills

• Fatigue and weakness

• Chest congestion and cough

• Headaches

In children, additional symptoms like nausea, vomiting, or diarrhea may occur. While sneezing, sore throat, and runny nose can accompany the flu, these are more common in colds. Severe flu cases may lead to complications such as pneumonia, sinus infections, or ear infections. Rarely, more serious conditions like heart or brain inflammation, organ failure, or sepsis can develop. Seek urgent medical care if you experience critical symptoms like:

• Difficulty breathing

• Persistent or worsening fever or cough

• Constant chest or abdominal pain

• Severe headaches, dizziness, or drowsiness

• Decreased urination or dark urine

• Severe muscle pain or extreme weakness

• Worsening of pre-existing medical issues

In children, watch for emergency signs like trouble breathing, bluish lips or face, ribs pulling with each breath, chest or muscle pain, seizures, dehydration, altered alertness, or reluctance to walk. A high fever, especially above 104°F, or any fever in infants under 12 weeks old, also requires immediate attention. Generally, flu symptoms peak between 2 to 7 days, but fatigue and weakness may linger for up to two weeks.

Diagnosis

Healthcare providers often diagnose the flu based on symptoms alone, but testing can confirm the presence of the influenza virus. Common tests involve swabbing the nose or throat, or occasionally collecting a sample of respiratory tract phlegm. Rapid influenza diagnostic tests (RIDTs) offer quick results, identifying influenza A in about 15 minutes, yet their accuracy may be limited. More precise testing, like rapid molecular assays, provides results ranging from 30 minutes to several days. Testing is not always required for treatment. A healthcare provider may prescribe medications or recommend home care based on symptoms, even without a positive test.

Medications

Symptoms can be managed at home with both over-the-counter (OTC) and prescription medications:

• OTC Treatments:

• Acetaminophen and Ibuprofen for fever and body aches

• Throat sprays or drops for sore throats

• Expectorant cough medicine (Guaifenesin) for chest congestion

• Cough suppressants (dextromethorphan) to reduce coughing

• Decongestants with pseudoephedrine for runny nose

• Saline nasal sprays for congestion relief

• Prescription Antivirals:

• Antiviral drugs like Oseltamivir (Tamiflu), Xofluza, Relenza, and Rapivab can cut flu symptoms short by one or two days if taken within 48 hours of onset.

Note that during peak flu times, medication shortages may occur. Antibiotics are not effective against the flu, as it is a viral, not bacterial, infection.