1. Red flag: Disappearing eyebrows
What it means: Shaved eyebrows are a fad (or fashion, if you will) in some circles. But when the outer third of the brow (the part closest to the ears) starts to disappear on its own, this is a common sign of thyroid disease — either hyperthyroidism (overactive thyroid gland) or hypothyroidism (underactive thyroid gland). The thyroid is a small but critical gland that helps regulate metabolism, and thyroid hormones are among those critical to hair production.
More clues: Brows tend to thin with age naturally. But with thyroid disease, the brow-hair loss isn’t evenly distributed; it’s a selective dropout on the ends. There’s usually a loss of hair elsewhere on the body, too, but the brows are so prominent, it’s often noticed here first. Early graying is a related sign of a thyroid problem. Women are more often affected than men, and hyperthyroidism especially strikes women in their 20s and 30s.
What to do: Mention this symptom to a dermatologist or your regular doctor. Most other symptoms of both hyper- and hypothyroidism are notoriously broad and general. Before you see a doctor, make note of any other changes you’ve noticed, possibly concerning weight, energy levels, bowel or menstrual regularity, mood, or skin changes.
2. Red flag: A stye that won’t go away
What it means: The vast majority of the time, a small, raised, often reddish bump along the inner or outer eyelid margin is just an unsightly but innocuous stye (also called a “chalazion”). But if the spot doesn’t clear up in three months, or seems to keep recurring in the same location, it can also be a rare cancer (sebaceous gland carcinoma).
More clues: Actual styes are plugged-up oil glands at the eyelash follicle. Fairly common, they tend to clear up within a month. A cancerous cyst that mimics a stye, on the other hand, doesn’t go away. (Or it may seem to go away but return in the same spot.) Another eyelid cancer warning sign: Loss of some of the eyelashes around the stye.
What to do: Point out a persistent stye to an ophthalmologist (a medical doctor who specializes in the eye). A biopsy can confirm the diagnosis. The stye is usually removed surgically.