Influenza usually starts with symptoms that are similar to a cold, such as fever, sore throat, nasal congestion, headache, and body aches. However, the symptoms of influenza quickly become worse than a cold. Most people with influenza have a fever and cough, or they have a fever and sore throat.

The most common symptoms of influenza include:

• Fever
• Cough
• Sore throat
• Muscle aches
• Body aches
• Fatigue
• Weakness
• Headache

Additional symptoms of influenza may include:

• Abdominal pain
• Anorexia
• Chest congestion
• Chest pain
• Chills
• Diarrhea
• Difficulty breathing
• Joint pains
• Nasal congestion
• Swollen glands
• Vomiting
• Wheezing