How Long Does the Flu Last?

Quick Answer

Influenza (the flu) lasts 5–7 days for most healthy adults. The worst symptoms — high fever, body aches, and chills — typically peak on days 2–3 and improve by day 5. Cough and fatigue often linger for 1–2 additional weeks.

Flu Symptom Timeline

• Day 1: Sudden onset of fever (101–104°F), chills, headache, muscle aches, fatigue
• Day 2–3: Symptoms peak — high fever, severe body aches, sore throat, dry cough
• Day 4–5: Fever begins to break, body aches start easing
• Day 5–7: Most acute symptoms resolve, appetite returns
• Week 2–3: Lingering cough, fatigue, and general weakness

Duration by Age Group

• Healthy adults (18–64): 5–7 days
• Children: 7–10 days (more severe symptoms common)
• Elderly (65+): 7–14 days, higher complication risk
• Immunocompromised: 7–14+ days

Flu vs. Cold vs. COVID

Feature	Flu	Cold	COVID-19
Onset	Sudden	Gradual	Variable
Fever	High (101–104°F)	Rare/mild	Common
Body aches	Severe	Mild	Moderate
Fatigue	Severe, lasting	Mild	Variable
Cough	Dry, can be severe	Mild	Dry, persistent
Congestion	Sometimes	Primary symptom	Sometimes
Loss of taste/smell	Rare	Rare	Common
Duration	5–7 days	7–10 days	5–14 days

Contagious Period

You're contagious from 1 day before symptoms start through 5–7 days after becoming sick. Children and immunocompromised people may be contagious longer. You're most contagious during the first 3–4 days of illness.

When Antiviral Treatment Helps

Oseltamivir (Tamiflu) and other antivirals can shorten the flu by 1–2 days if started within 48 hours of symptom onset. They're most important for:

• People 65 and older
• Children under 5
• Pregnant women
• People with chronic health conditions
• Immunocompromised individuals

How to Recover Faster

• Rest — your body needs energy to fight the virus
• Stay hydrated — water, broth, electrolyte drinks (fever increases fluid loss)
• Take OTC medications — acetaminophen or ibuprofen for fever and aches
• Use a humidifier to ease congestion and cough
• Stay home for at least 24 hours after fever resolves (without fever-reducing meds)
• Avoid alcohol and caffeine which can dehydrate

When to See a Doctor

Seek medical attention if:

• Difficulty breathing or shortness of breath
• Persistent chest pain or pressure
• Severe or persistent vomiting
• Fever above 104°F
• Symptoms improve then suddenly worsen (possible secondary infection)
• Confusion or altered mental state
• Symptoms last more than 10 days without improvement

Prevention

• Annual flu vaccine — reduces risk by 40–60% and severity if you do get sick
• Wash hands frequently with soap for 20 seconds
• Avoid close contact with sick people
• Cover coughs and sneezes
• Don't touch your face