Some people who have asthma are usually born with asthma and sometimes they develop asthma as a child or even later on in life.
It's possible to not have asthma as a child and then when you reach 30, 40, 50, 60 or even older you can then develop asthma.
So yes you can develop asthma later on in life even if you never experienced any symptoms of asthma before.
If you think you may be developing asthma you should see a doctor and have a test done such as the lung function test and get chest X Rays to see if you have asthma.
Asthma can be deadly if not treated so always get tested for asthma if you think you may have it because it can be serious.
If you do have asthma you need to keep an asthma inhaler with you at all times and use the inhaler and if you think your asthma is getting worse you need to call 911 to get medical attention fast.