Likely Cause: The flu Worse-Case Scenario: Sleep disorder Don’t dismiss daily fatigue as an inevitable consequence of aging. Feeling tired is a common symptom of two of the most prevalent sleep interrupters for midlife women: sleep apnea and restless legs syndrome, a neurological disorder that causes an itchy, twitchy sensation in the legs that makes it difficult to stay still and, as a result, fall asleep. "Many people think sleep apnea only affects overweight men, but it’s nearly as common in women after menopause," says Lisa Shives, MD, of Northshore Sleep Medicine, in Evanston, Illinois. Like sleep apnea, RLS often worsens as you get older. OTHER SIGNS IT MAY BE SERIOUS: If you’re a snorer and you wake up feeling as if you’ve been hit by a truck, chances are you have sleep apnea. The condition relaxes the muscles of the throat, making it difficult to get sufficient air, and the lack of oxygen triggers mini awakenings-sometimes hundreds of times a night. Other signs of sleep apnea: waking with a headache and sore throat; experiencing memory or concentration problems; feeling irritable or depressed. Fatigue-related symptoms such as irritability are also common with RLS. WHEN TO ACT: If the symptoms of either disorder persist for more than a month, see your internist, who may be able to diagnose the problem based on your description. If not, she may refer you to a sleep specialist for further evaluation. Sleep apnea is treated with a continuous positive airway pressure device, a mask that fits over your nose and/or mouth during sleep and helps open airways with gentle air pressure. RLS is treated with dopamine-like drugs, but some sufferers can control symptoms by limiting caffeine, walking regularly and massaging or stretching their legs before bedtime. Practicing yoga or meditation may relieve some symptoms. Likewise, lifestyle changes may ease the effects of sleep apnea: Drop pounds if you’re overweight, avoid alcohol, quit smoking, and try to sleep on your side, a position that sometimes reduces symptoms.

Likely Cause: Harmless skin growth Worse-Case Scenario: Skin Cancer While it’s common to develop new moles before midlife, finding a new one or seeing changes in an existing mole after age 40 could be a sign of melanoma, the deadliest type of skin cancer. OTHER SIGNS IT MAY BE SERIOUS: "If a mole-new or old-turns darker or black, becomes asymmetrical, or causes pain, itching or bleeding, you should get it checked out right away," says Robert Brodell, MD, a dermatologist in Warren, Ohio, who is a spokesperson for the American Academy of Dermatology. The more moles you have, the greater your risk for melanoma. Being fair and spending lots of time in the sun (even if you only did so in your youth) raises your risk, as does every single sunburn. "If you have lots of sun damage, like freckles, you have a higher risk too," Brodell says. WHEN TO ACT: "Call your dermatologist as soon as you notice something unusual and say, ‘I have a changing mole, and I’m worried about it.’ She should get you in within a week or two," Brodell says. If you don’t have a dermatologist, ask your doctor for a referral. The dermatologist should check your whole body for signs of skin cancer and biopsy anything that looks suspicious. "Fortunately, when melanoma is caught early it’s very curable," Brodell says. To protect your skin, apply a broad spectrum sunscreen with at least SPF 30 every day, have full-body screenings annually, and check your body for new or changing moles once a month.

Likely Cause: Gastrointestinal bug Worst-Case Scenario: Ovarian cancer Several medical groups, including the American Cancer Society, warned in 2007 that bloating and pelvic pain can be early signs of ovarian cancer- big news, since doctors have long believed that this often deadly disease is symptomless until it’s too advanced to treat. "If caught early, ovarian cancer is up to 90 percent curable," says Barbara Goff, MD, of the University of Washington. OTHER SIGNS IT MAY BE SERIOUS: Additional symptoms of ovarian cancer include feeling full quickly or having difficulty eating, urinating frequently or with great urgency, and changing bowel habits. You’re at increased risk if you have a family history of the illness, have tested positive for mutations in the genes BRCA 1 or BRCA 2, or have been on hormone therapy. (Your risks are lower if you have had at least one child, breast-fed a baby, taken birth control pills and maintained a healthy weight.) WHEN TO ACT: "If the symptoms are new, occur almost every day, last more than a few weeks and don’t go away if you eat more fiber, reduce your salt intake, or exercise more frequently, schedule an appointment with your gynecologist," says Linda R. Duska, MD, of the University of Virginia, in Charlottesville. Ask to be seen within two weeks. Diagnosis is tricky, so don’t be afraid to push your doctor for appropriate testing: a pelvic ultrasound and perhaps a blood test to check your level of CA-125, a substance found in high amounts in the blood of many women with ovarian cancer. Partly because the incidence of ovarian cancer rises with age, the ACS recommends annual pelvic exams for all women over age 40.

Likely Cause: A cold Worst-Case Scenario: Adult-onset asthma, a condition that can worsen as women enter midlife. OTHER SIGNS IT MAY BE SERIOUS: "If you cough only when you’re exercising or sleeping, that can indicate asthma," says Vincent Tubiolo, MD, of the American Academy of Allergy, Asthma and Immunology. Other symptoms include wheezing, particularly when you exhale; shortness of breath; and tightness in the chest. Risk factors are obesity, allergies, smoking and a recent respiratory tract infection. "Women who have taken estrogen for 10 years have a 50 percent higher risk of developing asthma," Tubiolo says. "And people with acid reflux are at increased risk, possibly because the acid irritates the airways and triggers an asthmatic cough." WHEN TO ACT: Asthma isn’t usually an emergency, but it makes sense to consult a doctor since the disease can be progressive (and even life-threatening when breathing problems are severe). Also, the condition can limit your physical activity and interfere with your sleep, both of which can affect your long-term health. Asthma is diagnosed with a pulmonary function test that measures airflow. "People feel a lot better once they receive treatment," Tubiolo says. Reduce your risk by avoiding smoke, including the secondhand variety, and maintaining a normal weight. UP NEXT: 12 Ways to cool hot flashes, click here.