Symptoms

At first, the flu may seem like a common cold with a runny nose, sneezing and sore throat. But colds usually develop slowly, whereas the flu tends to come on suddenly. And although a cold can be a bother, you usually feel much worse with the flu.

Common signs and symptoms of the flu include:

• Fever
• Aching muscles
• Chills and sweats
• Headache
• Dry, persistent cough
• Shortness of breath
• Tiredness and weakness
• Runny or stuffy nose
• Sore throat
• Eye pain
• Vomiting and diarrhea, but this is more common in children than adults

When to see a doctor

Most people who get the flu can treat themselves at home and often don't need to see a doctor.

If you have flu symptoms and are at risk of complications, see your doctor right away. Taking antiviral drugs may reduce the length of your illness and help prevent more-serious problems.

If you have emergency signs and symptoms of the flu, get medical care right away. For adults, emergency signs and symptoms can include:

• Difficulty breathing or shortness of breath
• Chest pain
• Ongoing dizziness
• Seizures
• Worsening of existing medical conditions
• Severe weakness or muscle pain

Emergency signs and symptoms in children can include:

• Difficulty breathing
• Blue lips
• Chest pain
• Dehydration
• Severe muscle pain
• Seizures
• Worsening of existing medical conditions