Dermatologists are like health detectives. One look at the outside can give them important information about what’s bubbling up on the inside. “The skin can be a good reflection of the overall health of the body,” says Marisa Potter, MD, a board certified dermatologist at Baumann Cosmetic & Research Institute in Miami, FL. Changes in your skin could be indicative of something as innocent as needing more sleep or an extra layer of moisturizer, but in the event it’s something more, you need to know. Here’s what symptoms could tip you off that there’s something more going on. Symptom: Raised, red patchesWhat it might mean: You may have psoriasis, an imbalance of immune cells that leach underneath skin and cause inflammation, which is what leads to those irritated patches of skin. “Some people have genes that make them more susceptible to this autoimmune disease,” says Marina Peredo, MD, assistant clinical professor of dermatology at Mount Sinai Hospital. Though you can get psoriasis at any age, she notices two peak times of diagnosis: one in people when they’re teenagers or in their early 20s and another when they’re in their 50s or 60s. The latter flare-up is often set off by a stressful event, like a death in the family or divorce. Strep throat is another common trigger of psoriasis. Peredo always asks her patients if they also have joint pain, stiffness, or swelling. That’s because 30% of psoriasis sufferers also have psoriatic arthritis, which is an autoimmune disease characterized by joint pain accompanied by psoriasis. If you have this condition, it’s not enough to simply treat skin with a steroid cream, so your dermatologist may refer to you to rheumatologist for treatment. And, be sure to monitor your health in other areas. “People with psoriasis may also have an increased risk for many other internal conditions like heart disease, cancer, and depression,” adds Potter. Symptom: Dry, itchy skin Photo by Fuse/Getty Images What it might mean: It’s probably “winter itch,” skin dryness that’s a result of cold, dry air. Using a humidifier, avoiding super hot showers, and routinely slathering on a thick moisturizer will help keep skin supple. But if it’s an intense itch (the kind that makes you leave scratch marks on your skin) and is accompanied by other symptoms like fatigue or weight loss, your doctor may want to rule out more serious conditions like thyroid problems, renal disease or certain cancers. “These diseases release inflammatory hormones that make skin really itchy,” says Peredo. MORE: 13 Genius Uses For Tea Tree Oil Symptom: AcneWhat it might mean: You’re stressed. As if you need anything else to worry about, there goes your face breaking out. When you’re hopped up on anxiety, your body releases cortisol, which can lead to breakouts, says Peredo. You’ll want to get on a good acne regimen; hormonal birth control has also been shown to help prevent pimples. It’s also important to learn calming strategies so you can simmer down both in the moment and after a harried day. Things like yoga, taking a few deep breaths, dancing to tunes in your home, or going for a walk around the block have all been shown to be stress busters. These 5 meditations can help you calm down fast. Symptom: Red bumpsWhat it might mean: It’s more than just stress. “Many times skin conditions are the outward appearance of psychiatric conditions,” says Ronald Sulewski, MD, a Chicago dermatologist at Pinski Dermatology & Cosmetic Surgery. Some people with anxiety and depression pick at their skin to cope with unhappy emotions, leaving red marks, bumps, or bleeding behind. In that case, a dermatologist would refer you to your primary care doctor or a psychiatrist to uncover and treat the root problem. Symptom: Acne and unwanted hair Photo by Peopleimages/Getty Images What it might mean: Unfortunately, acne’s not something you leave behind when you’re a teen; women of any age can get it. In your 30s and 40s though, you may notice acne on your chin and cheeks, plus unwanted hair (like on your stomach, face, or chest). That’s a symptom you might not think to mention to your dermatologist, but you must, says Potter. Your derm will want to run a blood test to check for a hormonal imbalance (like polycystic ovary syndrome, for example) and then may refer you to an endocrinologist for treatment. Symptom: Puffy eyelidsWhat it might mean: Swollen eyes may be from something as simple as skimping on shut-eye one night. “Sleeping on your stomach can also cause fluid accumulation around the eyelids,” says Potter. But if they look itchy, red, and scaly you may also have a seasonal allergy or be suffering from an allergic reaction. “The eyelids are covered with the thinnest skin on your body and will often show an allergy before any other place,” adds Peredo. Common allergies include fragrances, dyes in beauty products and clothing, and formaldehyde (a preservative in some creams, shampoos, and nail polish). Your dermatologist can run an allergy patch test to determine what ingredient is setting off your symptoms. Skin symptom: Yellow bumps on arms and legs or dark velvety patchesWhat it might mean: You should be screened for diabetes. “Yellow, waxy looking bumps can emerge on skin as the result of high triglyceride levels or diabetes,” says Peredo (The good news? Diabetes doesn’t have to be your fate; Rodale’s new book, The Natural Way To Beat Diabetes, shows you exactly what to eat and do to prevent the disease—and even reverse it). Dark, velvety patches of skin on the back of your neck and arms (“people will try to rub it off thinking it’s dirt, but it’s not,” she says) are another sign of diabetes. Though 29 million Americans have diabetes, one-quarter of them don’t know it, so skin symptoms may be one of the first clues.