Is susceptibility for asthma primarily determined in adulthood (around 20-25 years of age)?

Some people become diagnosed to have asthma before they reach the age of 5. This is why the given statement is false. A lot of people who have asthma have gotten this at an early age. Some adults start to develop asthma when they are already adults when they are always exposed to things that may cause them to be allergic.

Take note that the exact cause of asthma is unknown. Some are just more susceptible to it because it is in their genes. There are also instances when you may react more strongly to asthma as compared to your usual.