Final answer:
The exact odds of acquiring an STI during one's lifetime are not specified, as it varies based on behavior and changes over time. Certain STIs are more likely to be asymptomatic, potentially leading to underdiagnosis.
Step-by-step explanation:
The odds of acquiring an STI during a lifetime is a statistic that can vary based on numerous factors including behavior, prevalence of STIs in a population, and efforts towards education and prevention. While specific odds like 'one in four' or 'one in six' may be mentioned in various sources, there is not a universally agreed-upon lifetime risk number as it is constantly changing with new data and trends. Therefore, without a definitive source that provides a current estimate, I must refrain from providing a potentially incorrect answer. It's important to note that some STIs are often asymptomatic and certain behaviors can increase the risk of transmission. For example, chlamydia is a common STI that is often asymptomatic, particularly in females.