Symptoms:

The hallmark symptoms are:

• Cough
• Difficulty breathing
• Fever greater than 100.4 degrees F (38.0 degrees C)
• Other breathing symptoms

The most common symptoms are:

• Chills and shaking
• Cough -- usually starts 2-3 days after other symptoms
• Fever
• Headache
• Muscle aches

Less common symptoms include:

• Cough that produces phlegm (sputum)
• Diarrhea
• Dizziness
• Nausea and vomiting
• Runny nose
• Sore throat

In some people, the lung symptoms get worse during the second week of illness, even after the fever has stopped.

Signs and tests:

Your health care provider may hear abnormal lung sounds while listening to your chest with a stethoscope. In most people with SARS, changes on a chest x-ray or chest CT show pneumonia, which is typical with SARS.

Tests used to diagnose SARS might include:

• Blood clotting tests
• Blood chemistry tests
• Chest x-ray or chest CT scan
• Complete blood count (CBC)

Tests used to quickly identify the virus that causes SARS include:

• Antibody tests for SARS
• Direct isolation of the SARS virus
• Rapid polymerase chain reaction (PCR) test for SARS virus

All current tests have some limitations. They may not be able to easily identify a SARS case during the first week of the illness, when it is most important.