Flu Symptoms & Signs

The flu is a viral disease that tends to appear in the fall or winter each year. Flu symptoms can range from mild to severe, depending on your age and overall health. While most people recover from the flu with no lingering symptoms, more than 200,000 people are admitted to hospitals each year due to complications, according to the Centers for Disease Control and Prevention. Although it is not possible to prevent all cases of the flu, getting a flu shot can help reduce your risk of catching the virus.

Cause

• The flu, or influenza, is caused by a virus that affects the respiratory system. When an infected person sneezes, coughs or talks, the virus is released into the air and can be spread to other people. The flu can also be transmitted if you touch an object contaminated by the virus, such as a telephone or door handle, and then touch your eyes, mouth or nose. Influenza A, B and C, three separate strains of the virus, cause the flu. Although you are immune from getting a specific type of the flu again, types A and B mutate constantly, and new strains of the flu are always being produced.

Symptoms

• Symptoms of the flu include a sore throat, sneezing, runny nose, fever, headache, chills, cough, sweating, achy muscles, extreme fatigue, nasal congestion and loss of appetite. Vomiting and diarrhea may be present in children. While cold symptoms tend to occur gradually, flu symptoms start very suddenly and symptoms are more severe than cold symptoms. The flu usually lasts for about 1 week, although you may have a cough or feel tired for about 2 or 3 weeks after having the flu.

Risk Factors

• Flu symptoms can be severe, and even fatal, when the illness strikes young children or the elderly. People who are over age 50 are more at risk, as are nursing home residents. If you have a chronic condition, such as heart, kidney or lung disease or diabetes, recovering from the flu can be more difficult. You may develop complications of the flu, such as bronchitis or pneumonia. If you work in a hospital or doctor's office, your chances of catching the flu increase significantly. If you catch the flu while pregnant, you are at a higher risk of developing complications. Doctors recommend that people in any of these groups receive flu shots every year to lessen the chances of catching the flu.

Diagnosis

• Your doctor can diagnose a case of the flu in 30 minutes using a rapid flu test. While the test works quickly, it won't identify the strain of the flu. A blood sample may be needed to make this determination. Even without the test, your doctor will probably be able to make a diagnosis based on your symptoms alone, particularly if there is an outbreak of the flu in your area.

Treatment

• If you are diagnosed with the flu, your doctor will recommend rest, drinking fluids and using over-the-counter medications to help relieve your symptoms. Antiviral medications such as Tamiflu or Relenza can shorten the duration of your illness by a day or two if taken soon after your symptoms begin.