What is influenza?
Influenza is a viral respiratory infection caused by influenza A or B viruses. Unlike a common cold, flu typically hits suddenly with high fever, body aches, and exhaustion — within hours, not days. Adults catch flu about every 5 years on average; vaccination reduces both incidence and severity.
Most healthy people recover from flu without complications in about a week, but it can be serious for those over 65, pregnant patients, young children, and anyone with chronic heart or lung disease, diabetes, or compromised immune function. The CDC estimates 12,000–52,000 flu deaths per year in the US.
The key intervention is antiviral medication (most commonly oseltamivir/Tamiflu) started within 48 hours of symptom onset — it shortens illness, reduces severity, and may prevent complications.
Do I have influenza? Common signs
If most of these describe what you're experiencing, telehealth is a reasonable next step:
What causes it
Influenza A and B viruses spread person to person through respiratory droplets (coughs, sneezes) and contaminated surfaces. The flu season in the US typically runs October–May, peaking December–February. Influenza viruses constantly mutate, which is why annual vaccination is needed — last year's vaccine may not match this year's circulating strains.
Is it contagious?
Yes — very. Flu is contagious from about 1 day before symptoms appear until about 5–7 days after onset. Children and immunocompromised people may be contagious longer. Influenza spreads particularly well in indoor crowded settings during winter.
Tamiflu started within 48 hours shortens flu by about a day — and may prevent the worst of it for high-risk people.
Can it be treated online?
Flu is ideal for telehealth — diagnosis is largely clinical (your symptoms during flu season are usually enough), and the critical intervention is starting antivirals within 48 hours. Driving to clinic and waiting can eat into that window. A clinician can evaluate symptom timing, confirm classic flu features, screen for complications, and route Tamiflu (or alternatives) to your pharmacy.
How influenza is treated
Antivirals: oseltamivir (Tamiflu) 75 mg twice daily for 5 days is most commonly prescribed. Alternatives include baloxavir (single dose), zanamivir (inhaled), or peramivir (IV). All work best when started within 48 hours of symptoms — they shorten illness by about a day and reduce complications.
Supportive care: rest, fluids, acetaminophen or ibuprofen for fever and body aches, decongestants for nasal congestion. Do not give aspirin to children or teens with flu — it can cause Reye syndrome.
Self-care while you wait
- Rest — fight the urge to push through
- Drink plenty of fluids (water, broth, electrolyte drinks)
- Take acetaminophen or ibuprofen for fever and aches
- Use a humidifier or breathe steam
- Stay home and isolate from family — flu spreads fast
- Get the flu shot before next season (and consider one this year if you haven't)
- Wash hands frequently
How long does it last?
Most healthy adults feel significantly better within 5–7 days. Cough and fatigue can linger 1–2 weeks. Children, older adults, and those with chronic conditions may take longer. If you're improving then suddenly worsening, that often signals a bacterial complication like pneumonia and needs immediate evaluation.
Frequently asked questions
Is it too late for Tamiflu?
Tamiflu works best within 48 hours of symptom onset. After 48 hours, the benefit is smaller, but it may still be worth considering for high-risk patients or hospitalized people. Within the window — start as soon as possible.
Cold or flu — how to tell?
Flu hits suddenly with high fever, severe body aches, and exhaustion. Colds build gradually with runny nose, sneezing, mild sore throat, and minimal fever. If you're still upright and functional, it's probably a cold.
Should I get tested?
A rapid flu test can help confirm, but during flu season, classic symptoms are often enough. Testing is most useful for high-risk patients to confirm before starting Tamiflu, or in patients whose symptoms are ambiguous.
Can I get flu and COVID at the same time?
Yes — "flurona" exists. They have overlapping symptoms; testing can distinguish. Treatment differs (Tamiflu for flu, Paxlovid for COVID in high-risk patients).
Will the flu vaccine still help if I've already caught it?
For this episode, no — but vaccination protects against multiple strains, so you could still be exposed to a different one this season. Worth getting if you haven't.
