Below is an instruction from Human. Write a response.
    ### Instruction:
    What causes Bronchitis ?
    ### Response:
    Acute Bronchitis
                
Infections or lung irritants cause acute bronchitis. The same viruses that cause colds and the flu are the most common cause of acute bronchitis. Sometimes bacteria can cause the condition.
                
Certain substances can irritate your lungs and airways and raise your risk for acute bronchitis.
    