When the flu (influenza) leads to Pneumonia

Battling the flu can tax your immune system and increase the chances that you'll develop pneumonia. To help prevent other infectious organisms from gaining a foothold in the lungs, drink lots of liquids. Avoid taking antihistamines, which can dry and thicken secretions in the respiratory tract. Also, try to avoid smoking and drinking excessive alcohol, which can interfere with the body's natural mechanisms that flush out invading organisms. Taking these simple precautions can help you recover from the flu and help prevent pneumonia and other illness. - American Lung Association

Symptom Cold Flu Pneumonia
Fever Rare Characteristic, high (over 101 F) lasting 3-4 days Characteristic, high and rises rapidly (up to 105 F)
Headache Rare Prominent Generally no
Muscle aches and pains Slight Usual and often severe Occasionally
Fatigue Mild Early, prominent and can last up to 2 to 3 weeks Occasionally
Stuffy/runny nose Common Sometimes Generally no
Sore, scratchy throat Common Sometimes Generally no
Chest discomfort/pain Mild to Moderate Common Common
Cough Common Generally a dry hacking cough Moist cough; may produce rust-colored sputum or pus
Onset of Symptoms Gradual Rapid Gradual