How can you tell whether you have the flu?

People often use the terms “cold” and “flu” interchangeably. However, they are two different illnesses which progress very differently and have different consequences. You can normally tell whether you have a cold or the flu by observing the signs and symptoms.

Colds are far more common than the flu. You are more likely to have a cold or another upper airway infection if:

• the illness developed gradually,
• you do not have an achy body,
• it is outside the flu season or nobody around you has the flu,
• you do not have any serious chest complaints, and
• you still feel like eating.

The flu (influenza) typically affects your whole body rather than just your airways. The symptoms tend to arise very suddenly and be very strong. Typical flu symptoms include:

• a fever: Your body temperature rises to 38 to 40 degrees centigrade or more,
• aches and pains in the muscles and joints throughout your body (“myalgia” and “arthralgia”),
• headaches,
• feeling exhausted and generally very ill,
• a dry cough without phlegm,
• a stuffy and / or runny nose (“rhinitis”),
• a lack of appetite, and
• extreme tiredness.

Babies or toddlers might have gastro-intestinal symptoms too, like feeling sick and vomiting.

It is advisable to consult a doctor if you think that you or someone you know has the flu. This is especially important if you already have another illness, such as a chronic lung disease or diabetes, which increases the likelihood that your flu will lead to complications. The same is true if you are in close contact with people who are at higher risk, including babies and toddlers.

 

Author: German Institute for Quality and Efficiency in Health Care (IQWiG)

© IQWiG (Institute for Quality and Efficiency in Health Care) Last update of this website: 02/03/2012