Some people don’t show signs of having asthma until they are adults. This is known as adult-onset asthma.
What causes adult-onset asthma? There are many possible factors.
Sometimes, people just manage to essentially avoid their asthma triggers for years. When they are then exposed to that trigger as an adult, it can bring on asthma symptoms. For example, they may move in with a roommate who has a pet, or they may work around certain chemical fumes for the first time.
Other times, a viral infection can unmask their asthma symptoms. For example, they may have an upper respiratory infection that leads to a cough that sticks around for weeks.
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