Note: This is one of the many signs/symptoms that you may find to be so common and applicable to so many different ailments as not to be a useful differentiator. A cough is a reflex, which helps protect the body. Coughing removes the mucus and foreign irritants from the body. Never a diagnosis on its own, a cough is always a symptom of something else.

Cough Overview -Medline

Cough Overview - WebMD
This link offers some information on the different kinds of coughs –productive and unproductive

You can hear and observe a patient coughing.

• Common Cold


• Infections, including:
  
  
  • Leukemic Meningitis
  
  
  • Mycobacterial Meningitis
  
  
  • Chemical Meningitis
  
  
  • Viral Meningitis
  
  
  • Bacterial Menigitis
  
  
  • Fungal Meningitis
  
  
• Tuberculosis


• Bronchitis


• Pneumonia


• Lung Disease


• GERD


• Allergies


• Asthma


• Some medicines


• Influenza

Click here for an overview of possible causes.