Symptoms

The signs and symptoms of flu caused by the H1N1 virus are similar to those of infections caused by other flu strains and can include:

• Fever, but not always
• Chills
• Cough
• Sore throat
• Runny or stuffy nose
• Watery, red eyes
• Body aches
• Headache
• Fatigue
• Diarrhea
• Nausea and vomiting

Flu symptoms develop about one to three days after you're exposed to the virus.

When to see a doctor

It's not necessary to see a doctor if you're generally healthy and develop flu signs and symptoms, such as fever, cough and body aches. Call your doctor, however, if you have flu symptoms and you're pregnant or you have a chronic disease, such as asthma, emphysema, diabetes or a heart condition, because you have a higher risk of flu complications.

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