What Foot Health Tells Us About Other Illnesses

Your feet are a vital part of your anatomy — and not just for helping you get from the couch to the kitchen. They’re composed  of more than 50 bones, 60 joints and 200 muscles, tendons and ligaments that can offer important clues about what’s happening throughout the rest of your body. By paying attention to subtle shifts in the shape, flexibility and even temperature of your feet, you can get an early jump on larger health issues.

Changing Shape and Size 

Most of us have experienced sore or injured feet from poorly fitted shoes, or excessive walking, running or standing. There’s nothing unusual about that. But changes to the shape or size of your foot are a different matter and might warrant a trip to the doctor. Some things to watch for:

• Pitted or moon-shaped nail beds. Spoon-like indentions (or sunken nails) on your toe bed could suggest a chronic iron deficiency. Pitted nails, or those separating from the nail bed, could indicate psoriatic arthritis, an inflammatory disease of the joints affecting 30 percent of people who deal with psoriasis.

• Enlarged big toe. A suddenly swollen and painful big toe could mean gout, a disease in which tiny crystals are deposited in abnormal places such as your joints and soft tissue.

• Thick or falling-off nails. This change is usually the result of a fungal infection. It could be caused by something as simple as coming into contact with a fungus in a damp or wet environment. But it also could be a sign the body is negatively responding to an autoimmune disorder or treatment.

• Hair loss. Losing hair on the toes and legs could indicate peripheral arterial disease (PAD), a narrowing of arteries in the legs and feet linked to increased risk of heart disease. 

Changes in Mobility

Decreases in the mobility or flexibility of your foot also may signal a more substantial problem is brewing.

• Numbness. Tingling and numbness in your feet could indicate a damaged nerve condition called peripheral neuropathy. It can be brought on by injury, but also is an early sign of diabetes or vascular problems.

• Inability to lift front of foot. This muscular issue, called a foot drop, is linked to several  neurodegenerative brain disorders, including multiple sclerosis, stroke and Lou Gehrig’s disease.

• Stiff or sore toe joints. This could be an early warning of rheumatoid arthritis, an autoimmune disease affecting the tissue lining around your joints. If tenderness runs along the bottom of your feet to your heel, it could be plantar fasciitis, an inflammation of the thick band of tissue, the fascia, which connects the heel to the toes.

• Swelling. Unusual swelling in your feet or ankles could be caused by high blood pressure due to congestive heart, kidney or liver failure.

Cold Feet 

Let’s not confuse this with the anxiety you feel when making a difficult decision. If your feet are actually cold when they shouldn’t be, your doctor may want to consider these two issues:

• Blue toes. If the tips of your toes are going numb and turning blue or white, you may have Reynaud’s disease, a rare disorder of the blood vessels that causes them to narrow when cold or stressed. 

• Cold feet (and body). You could have an underactive thyroid. Hypothyroidism is the most common thyroid issue, primarily affecting women after menopause. If left unchecked, it can impact your heart, nervous system, muscles and weight.

Diabetes

Foot ailments are associated with a wide range of illnesses. But often this is the primary location for visible symptoms of diabetes. Open wounds or corns/calluses that resist healing are among the signs that you should see your doctor, who may set up a screening and discuss lifestyle changes and medication.