Asthma is a long-term (chronic) disease of the respiratory system. It causes your airways to tighten and become narrow. This makes it hard to breathe and may cause wheezing and coughing.
Even though asthma is a lifelong disease, most people can lead active lives by following a treatment plan, avoiding things that cause flare-ups, and taking medicine.
The cause of asthma is not clearly known.
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