10 subtle signs on your feet that indicate disease

Learn how to spot signs on your feet that could indicate serious illnesses such as diabetes, thyroid conditions and heart disease, even before you see a doctor.

Your feet are dry and scaly

You may have thyroid problems, especially if a moisturizer doesn’t correct the situation. When the thyroid gland (a butterfly-shaped gland at the base of the neck) becomes diseased, it produces less thyroid hormone, which regulates metabolism, blood pressure, tissue growth and the development of the osteomuscular and nervous systems. Marlene Reid, a podiatrist in Napierville, Illinois, explains, “Thyroid problems cause dry skin. When we notice cracked skin on the feet or if a moisturizer doesn’t make the dryness go away in a few days, we suggest patients see their doctor to make sure their thyroid gland is healthy.” Brittle nails can also signal thyroid problems.

Hairless toes

You may have arterial disease. If the hair on your toes suddenly disappears, it could indicate poor circulation caused by peripheral arterial disease (PAD). “Symptoms include decreased hair growth on the feet and ankles, purple toes and thin or shiny skin,” says Suzanne Fuchs, a podiatric surgeon at North Shore University Hospital in New York City. PAD, a buildup of plaque in the arteries of the legs, affects about 8 million Americans. The symptoms are almost imperceptible, but doctors can detect it by taking a pulse from the foot pad or by a spot on an X-ray. “When I notice hardening of the arteries on an x-ray of a fractured foot, I’m 99 percent certain of a similar condition in the myocardial blood vessels,” says Gary A. Pichney, a podiatric surgeon with the Institute for Foot and Ankle Reconstruction at Mercy Medical Center.

Sores that don’t heal

“This could be an indication of diabetes. Uncontrolled blood sugar damages the nerves and causes poor circulation, so blood doesn’t get to the feet. When blood doesn’t get to a wound caused, for example, by rubbing shoes, the skin doesn’t heal properly. Many diabetics are diagnosed with foot problems,” says Dr. Reid. Other symptoms of diabetes include tingling or numbness in the feet. Ask your doctor for a blood sugar test.

Painful inflammation of the big toe

This could be an attack of gout, a type of arthritis that usually affects the big toe joint. Eating only steak and wine? Foods high in purine, a chemical compound found in red meats, fish and some alcohols, can trigger a gout attack by raising the level of uric acid in the body. Uric acid is normally excreted in the urine, but can be produced in large amounts, or not excreted enough, in some people. “Most often, you see the deposition of uric acid in the big toe or ankle,” says Bob Baravarian, a podiatrist and foot and ankle specialist at Providence Saint John’s Health Center in Santa Monica, Calif. The patient wakes up with a red, swollen joint. It’s extremely painful.” If necessary, a physician prescribes anti-inflammatory drugs for relief and suggests a low-purine diet for prevention.

Tiny red lines under a nail

This could be a heart infection. Red streaks under the toenails or fingernails are evidence of ruptured blood vessels, called thread-like hemorrhages. They occur when small blood clots damage the capillaries under the nails. They may indicate endocarditis, an infection of the inner lining of the heart. People who have heart disease, a pacemaker, or a weakened immune system (such as cancer patients undergoing chemotherapy, people with HIV, and people with diabetes) are more likely to develop endocarditis. This infection leads to heart failure if left untreated. If you notice thread-like bleeding under your fingernails without prior trauma, see your doctor and ask for an evaluation of your heart and blood flow.

Deformity in your feet

It could be lung cancer or heart disease. Golf club-like deformity of the bony epiphyses in the toes and fingers is often synonymous with lung cancer, chronic lung infection, heart disease or bowel disease. Lung cancer and heart disease decrease vascular resistance, which increases blood flow to the small arteries in the toenails and fingers, swells the tissues and causes deformation of the bony epiphyses (fingers and toes become rounder and wider). Although patients are usually aware that they have a disease that causes the deformity, it is best to consult your physician.

The surface of the nails is riddled with holes

This could be psoriasis. If you see small holes, grooves or ridges in your toenails, you may have nail psoriasis. Although most people who have nail psoriasis also have generalized psoriasis (an autoimmune disease that parchment and irritates the skin), 5% of people with nail psoriasis are not affected elsewhere. “If you’ve never been found to have psoriasis, but your nails are cracked, you should seek help,” Pichney says. Other symptoms include white spots and horizontal lines on the nails. To treat psoriasis, your doctor may prescribe topical creams or steroids to inject under the nail.

Spoon-shaped nails

You may have anemia or lupus. Is there a depression in your nail deep enough to hold a drop of water? Also known as koilonychia, spoon-shaped nails can indicate iron deficiency, hemochromatosis (an overproduction of iron), Raynaud’s disease (which affects the blood supply to the extremities) and sometimes lupus erythematosus (an autoimmune disease that causes the immune system to attack cells, tissues and organs). Spoon nails sometimes appear in infants, but this corrects itself in the first few years of life. If you notice a spoon nail, see your doctor. Your doctor will do a blood test to find out the exact cause.

Straight line under your nails

This could be skin cancer. A dark vertical line under a fingernail could indicate malignant melanoma of the extremities or hidden melanoma, a form of skin cancer that appears on less visible parts of the body. Other hidden melanomas are melanomas of the eye and mouth. “A black line appears that runs from the base of the nail to the tip,” says Pichney. The patient should see a podiatrist or dermatologist to make sure it’s not a fungus (usually brownish yellow in color, and the line is not continuous).” Although only 5% of all diagnosed cases of melanoma are of the hidden kind, it is most common in dark-skinned people.

Increased arching of the foot

This could be a result of neurological damage. “Most highly arched feet are associated with some form of underlying neuromuscular condition,” says Pichney. If someone sees thinning of the plantar muscles, it could indicate a neurological disease called Charcot-Marie-Tooth (CMT).” This inherited disease damages peripheral nerves (nerves other than those in the brain and spinal cord). CMT can also cause changes in gait, numbness, difficulty keeping balance, loss of muscle in the legs and, later, similar symptoms in the arms and hands. See your doctor if you notice any abnormalities. “Any time you notice changes in your feet, see a podiatrist immediately,” Dr. Reid suggests.