“You can detect everything from diabetes to nutritional deficiencies just by examining the feet,” says Jane Andersen, DPM, president of the American Association of Women Podiatrists and a spokeswoman for the American Podiatric Medical Association.
Together, your feet contain a quarter of the body’s bones, and each foot also has 33 joints; 100 tendons, muscles, and ligaments; and countless nerves and blood vessels that link all the way to the heart, spine, and brain.
So when the feet send you one of these 10 warning signs, you should listen:
1. Toenails with slightly sunken, spoon-shaped indentations
What it means: Anemia (iron deficiency) often shows up as an unnatural, concave or spoonlike shape to the toes’ nail beds, especially in moderate-to-severe cases. It’s caused by not having enough hemoglobin, an iron-rich protein in the blood cells that transports oxygen. Internal bleeding (such as an ulcer) or heavy menstrual periods can trigger anemia.
More clues: On fingers as well as toes, the skin and nail beds both appear pale. The nails may also be brittle, and feet may feel cold. Fatigue is the number-one sign of anemia, as are shortness of breath, dizziness when standing, and headache.
What to do: A complete blood count is usually used to diagnose anemia. A physical exam may pinpoint a cause. First-step treatments include iron supplements and dietary changes to add iron and vitamin C (which speeds iron absorption).
2. Sudden hair loss on feet or toes
What it means: Poor circulation, usually caused by vascular disease, can make hair disappear from the feet. When the heart loses the ability to pump enough blood to the extremities because of arteriosclerosis (commonly known as hardening of the arteries), the body has to prioritize its use. Hairy toes are, well, low on the totem pole.
More clues: The reduced blood supply also makes it hard to feel a pulse in the feet. (Check the top of the foot or the inside of the ankle.) When you stand, your feet may be bright red or dusky; when elevated, they immediately pale. The skin is shiny. People with poor circulation tend to already know they have a cardiovascular condition (such as heart disease or a carotid artery) yet may not realize they have circulation trouble.
What to do: Treating the underlying vascular issues can improve circulation. Toe hair seldom returns, but nobody complains much.
3. A sore that won’t heal on the bottom of the foot
What it means: This is a major clue to diabetes. Elevated blood glucose levels lead to nerve damage in the feet — which means that minor scrapes, cuts, or irritations caused by pressure or friction often go unnoticed, especially by someone who’s unaware he has the disease. Untreated, these ulcers can lead to infection, even amputation.
More clues: Oozing, foul-smelling cuts are especially suspect because they’ve probably been there awhile. Other symptoms of diabetes include persistent thirst, frequent urination, increased fatigue, blurry vision, extreme hunger, and weight loss.
What to do: Get the ulcer treated immediately and see a doctor for a diabetes evaluation. Diabetics need to inspect their feet daily (older people or the obese should have someone do this for them) and see a healthcare professional every three months.
4. Cold feet
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.
5. Thick, yellow, 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.
6. Numbness in both feet
What it means: Being unable to “feel” your feet or having a heavy pins-and-needles sensation is a hallmark of peripheral neuropathy, or damage to the peripheral nervous system. That’s the body’s way of transmitting information from the brain and spinal cord to the entire rest of the body. Peripheral neuropathy has many causes, but the top two are diabetes and alcohol abuse (current or past). Chemotherapy is another common cause.
More clues: The tingling or burning can also appear in hands and may gradually spread up to arms and legs. The reduced sensation may make it feel like you’re constantly wearing heavy socks or gloves.