Along with baking your skin in the sun sans sunblock, a lack of sleep is health and beauty’s biggest enemy.While you’re out like a light each night, your body is hard at work making repairs and healing cells and tissues, including your skin. Not getting enough sleep (less than seven hours) cuts this crucial repair time short and wreaks havoc on your health and your skin.A continual lack of shut-eye has been linked to an increased risk of weight gain, type 2 diabetes and high blood pressure. Plus, when you don’t enough shut-eye, fine lines are more noticeable and dark circles crop up.QUIZ: How’s Your Sleep?When to bring it up: Most of us struggle to catch enough z’s on a nightly basis. In fact, 50 to 70 million Americans are affected by chronic sleep disorders and intermittent sleep problems that can significantly affect health.So when are your sleep troubles doctor-worthy? “First and foremost, if you think it’s a problem, then it’s a problem,” says Beth Ricanati, M.D., YouBeauty Wellness Advisor. “Why is that? We all require different amounts of sleep and though ideally, six to eight hours are the magic numbers, some of us need less and some more. If someone else tells you that you snore or if you are so tired during the day that it’s affecting your ability to do your normal activities, it warrants a discussion with your physician.”Snoring and unexplained fatigue can signs of sleep apnea, a dangerous sleep condition characterized by abnormal breathing that can be life-threatening. If you suspect sleep apnea, it’s best to see a sleep specialist.MORE: How Sleep Affects Your SkinOther more subtle red flags to look out for: “Falling asleep the minute your head hits the pillow or knowing you’re the kind of person to say, ‘I can fall asleep anytime, anywhere’—that’s a sign of sleep deprivation,” says Dr. Lisa Shives, M.D., medical director of Northshore Sleep Medicine in Evanston, Il. “Another big red flag is if you feel tired and are dragging even though you get seven to eight hours of sleep. There may be something wrong with the quality sleep.”In general, if you’re plagued by a sleep problem, such as insomnia, for two weeks in a row, it’s time to see a sleep specialist to get a diagnosis and treatment, according to James Nicolai, M.D., YouBeauty Integrative Health Expert and the medical director of the Andrew Weil, M.D. Integrative Wellness Program  at Miraval Arizona Resort and Spa in Tucson.Talking points: Book an appointment with your primary care physician—or better yet, with a sleep specialist—to exclusively talk about your sleep problem, recommends Dr. Shives. “Sleep can be considered a ‘soft symptom’ – not like ‘I have a large lump in my breast’ or ‘I have chest pain,’” she says. “The way to get their attention about something like sleep is by saying that’s the only reason you’ve gone there today.”MORE: How Much Sleep Do You Need?Come prepared to the appointment. Dr. Ricanati recommends asking yourself these questions and writing down your answers to share with your doctor: How long have you not been sleeping well? What was a normal night’s sleep for you before you noted a problem? Is it affecting you during the day? Has anyone else mentioned to you that you snore? Can you fall asleep but have trouble staying asleep? Do you wake up early and can’t go back to bed? How much caffeine do you drink? How much alcohol do you drink? Do you feel depressed?“The more you can characterize what you believe is going on, the easier it will be for you and your physician to do the detective work,” says Dr. Ricanati.