Flu symptoms usually appear suddenly. Influenza is a virus that attacks the respiratory system, especially the nose, throat and lungs. The flu is a contagious disease, according to the Centers for Disease Control, that makes about 60 million Americans sick every year from November to April. The World Health Organization says the best way to prevent transmission of the flu is vaccination. The flu can have very serious complications, including dehydration, pneumonia, ear and sinus infections in children and the worsening of chronic conditions such as diabetes and asthma.
Fever
The flu is usually associated with a high fever over 100 degrees F, according to MayoClinic.com. Fever is the body's defense against the intruding influenza virus. Chills and sweats may accompany the fever as the body's temperature rises and falls.
Body Aches
Body aches can be symptomatic of the flu, especially in the muscles of the legs, back and arms. Fatigue commonly accompanies body aches, and sometimes this exhaustion is extreme. Rest is encouraged but the victim of influenza may find it difficult to sleep due to body aches, despite how tired he may feel. The patient may have a general feeling of being unwell, known as malaise. This malaise can be extreme, and severely impede on his ability to go about activities of daily living.
Cough
A scratchy throat is also common with influenza, and this scratchiness may also lead to coughing, which may aggravate existing conditions like asthma. Pneumonia may also become a complication of influenza. Since influenza is spread through respiratory droplets, patients should cover their nose and mouth when coughing, and wash their hands frequently to prevent transmission to others.
Stuffy Nose
The influenza virus may cause inflammation of the nasal passages which results in a stuffy nose. The nose may become runny. Sinus pressure and congestion may accompany stuffy or runny nose. Post nasal drip will often contribute to coughing as well.
Nausea and Loss of Appetite
The flu victim may suffer nausea along with a loss of appetite, although MedlinePlus reports influenza rarely causes an upset stomach.
Headache
Headache may be present. The headache may or may not be the result of the fever. Sinus infections may accompany or become a complication of the influenza viruses, which may result in headache. Headache may be treated with over-the-counter pain relievers.
Other Symptoms
Other symptoms may be present with influenza, such as dizziness and ear pain. Influenza strikes each patient a little differently but most of the symptoms usually disappear for everyone within 5 days.
