What are the common symptoms of the flu?

Health officials outline typical influenza symptoms and guidance.

Public health officials and clinicians say influenza most commonly begins abruptly with fever and respiratory and systemic symptoms. Typical early signs include high fever, often 102°F (39°C) or higher; cough; sore throat; and nasal congestion or a runny nose. Patients frequently report severe muscle aches and body pain, persistent headaches, and pronounced fatigue that can last several days.

Clinicians emphasize that cough is usually dry and can progress to productive cough if bronchitis develops. Gastrointestinal symptoms such as nausea, vomiting and diarrhea are more common in children than adults but can occur at any age. Symptoms generally appear one to four days after exposure and peak within two to three days.

Health experts caution that some individuals, including older adults, young children and people with chronic medical conditions, may present atypically, sometimes without fever. Rapid worsening of symptoms, difficulty breathing, chest pain, altered mental status or signs of dehydration warrant immediate medical evaluation, clinicians say.

Treatment options include supportive care, rest, adequate fluids and antipyretics, and, when appropriate, antiviral medications prescribed by a clinician. Antivirals are most effective when started within 48 hours of symptom onset, experts note. Prevention remains central: annual vaccination, hand hygiene and staying home when ill reduce transmission.

Public health authorities routinely monitor circulating strains and issue guidance each season. Clinicians recommend that individuals consult their healthcare provider for personalized advice and that caregivers seek prompt care for infants, elderly relatives or immunocompromised household members. Such measures aim to reduce complications, hospitalizations and strain on healthcare systems.

Dr. Maria Lopez, an infectious disease specialist at City Medical Center, said vaccination reduces severe illness risk and recommended annual influenza vaccines for people six months and older; she advised urgent care for persistent high fever, severe breathing difficulty or confusion.