If you see: Shortened eyebrows
It could mean: Thyroid disorder
Hold a pencil perpendicular to the outer corner of your eye; if your eyebrow falls short of the pencil, it could indicate an underactive thyroid. Thyroid hormones have many functions, and one of them is to regulate how quickly your cells replenish themselves. When your levels of thyroid hormones are out of whack, the effect can be seen in almost every cell in your body, even your hair follicles. (You may also notice that the hair on your head has become thinner and drier.) Some other telltale symptoms include weight gain, fatigue, and constipation.
What to do: Your doctor can administer a blood test to measure your hormone levels. If they're low, you'll need prescription medication to restore them to normal levels.
If you see: Long ring fingers
It could mean: A higher risk of osteoarthritis
According to a 2008 study in the journal Arthritis & Rheumatism, women whose ring fingers are longer than their index fingers may be twice as likely to suffer from osteoarthritis. Though scientists aren't sure why the connection exists, it may be related to testosterone exposure in the womb. Longer ring fingers are linked to higher prenatal levels of testosterone. This lowers the concentration of estrogen, which is critical to bone development. Finger length also has a notable implication for the opposite sex: If a man's index finger is longer than his ring finger, his risk of prostate cancer drops by a third.
What to do: If you're overweight, losing just 5 percent of your body weight can help reduce your risk of knee osteoarthritis (one of the most common types), according to a 2009 study by the University of North Carolina at Chapel Hill.
If you see: Yellow nails
It could mean: Diabetes
Discolored nails may simply indicate an infection, but if you're also making extra trips to the bathroom, constantly reaching for your water bottle, and feeling fatigued, a likely culprit is diabetes. The condition can cause glucose to attach to collagen proteins in the nail, turning them from pink to yellow.
What to do: See your doctor for a diabetes test. If it's positive, he can recommend a combination of lifestyle changes and medication to keep the disease under control.
If you see: Thick, dark facial or body hair
It could mean: Polycystic ovary syndrome (PCOS)
Many women see a few wisps on their upper lip, but coarse, dark hair that shows up in unusual places—like the chin, cheeks, chest, abdomen, or back—can signal a hormone imbalance associated with PCOS. Women with this condition, in which the body produces more androgens (male sex hormones) than usual, may also experience irregular periods and cystic acne and have a hard time maintaining a healthy weight.
What to do: See your doctor for a blood test to check your hormone levels. PCOS increases your risk for diabetes and infertility, but lifestyle changes (such as quitting smoking and losing weight) and hormone-regulating medications (such as birth control pills) can help reduce symptoms and prevent complications.
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