Shaving a few years—or even a few decades—off of your age at the doctor's office might feel more like stretching the truth than telling a lie, but it can ultimately prevent your doctor from doing their job properly. For instance, if you were to say you're in your 30s instead of revealing that you're actually in your late 40s, your doctor might mistake those hot flashes as a symptom of hyperthyroidism instead of a symptom of menopause.