Clues your feet give about your health, 5-6

What it means: Women, especially, report cold feet (or more precisely, their bedmates complain about them). It may be nothing -- or it may indicate a thyroid issue. Women over 40 who have cold feet often have an underfunctioning thyroid, the gland that regulates temperature and metabolism. Poor circulation (in either gender) is another possible cause.

More clues: Hypothyroidism's symptoms are pretty subtle and appear in many disorders (fatigue, depression, weight gain, dry skin).

What to do: Insulating layers of natural materials work best for warmth. (Think wool socks and lined boots). If you also have other nagging health complaints, mention the cold feet to your doctor. Unfortunately, however, aside from treatment with medication in the event of a thyroid condition, this tends to be a symptom that's neither easily nor sexily resolved.

6. Red flag: Thick, yellow, downright ugly toenails

What it means: A fungal infection is running rampant below the surface of the nail. Onychomycosis can persist painlessly for years. By the time it's visibly unattractive, the infection is advanced and can spread to all toenails and even fingernails.

More clues: The nails may also smell bad and turn dark. People most vulnerable: those with diabetes, circulatory trouble, or immune-deficiency disorders (like rheumatoid arthritis). If an older person has trouble walking, sometimes the problem can be traced to the simple fact that as infected nails grow thicker, they're harder to cut and simply go ignored to the point of pain.

What to do: See a foot specialist or your regular physician for care and treatment. In serious cases, over-the-counter antifungals are usually not as effective as a combination of topical and oral medications and the professional removal of diseased bits. Newer-generation oral antifungal medications tend to have fewer side effects than older ones.