ADHD is one of the most difficult diagnoses to make accurately. ADHD frequently goes undiagnosed or misdiagnosed for years as another condition like anxiety or depression. Genuine ADHD symptoms can also overlap or mimic other conditions, again leading to misdiagnosis. One large national study found that only half of those who genuinely had ADHD were currently treated, because the diagnosis so frequently goes unrecognized by both the individual and the family physician.
Self-tests can be informative and even fun, but they can’t replace the accuracy of meeting with a professional who specializes in ADHD. As national experts recommend, a professional evaluation should include careful interviewing with you and at least one family member or significant other, review of any old records available (e.g. school records), and a scientifically-validated test (which self-tests aren’t). So, if you do some reading or take some self-tests that do make ADHD sound like your story, please do meet with a professional well-trained in ADHD rather than jumping to conclusions from what you’ve found online. You can always take these self-test results to review with a professional.