Over the past six months or so, I’ve been experiencing brain fog, fatigue, difficulty concentrating, fertility problems, and increased fat around my midsection. Being in my early 40s, I’m at the age when talk starts turning to perimenopause—also known as the menopausal transition, or the roughly 10 years leading up to the cessation of periods. When I’ve told friends and family members about what I’ve been going through, some have asked whether it could be perimenopause.