7 Surprising Health Issues You Didn’t Know Were Linked to Your Feet

When it comes to addressing their overall health and well being, few people put their best foot forward.

Despite the critical role that feet play in everyone’s day-to-day life — managing hundreds of tons of force and supporting vital organs — many people disregard the importance of the 42 muscles, 26 bones and 33 joints that they shove into their stylish stilettos or retro sneakers every morning.

But, according to Brooklyn, N.Y.–based podiatric surgeon Dr. Allyssa Knowles, not paying attention to one’s feet can have serious consequences.

While broken toes, sprained ankles and foot conditions, such as plantar fasciitis, may readily come to mind when many people think of foot-related disorders, Dr. Knowles says that many more serious health conditions can first present themselves in the feet.

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“A great percentage of the time when patients come to me [suspecting] that they have a foot condition, it turns out to be in relation to some other systemic disease,” Dr. Knowles said. “It happens much more often than you may think.”

In fact, Knowles says there is a direct correlation between systemic diseases and podiatric care that is often taken for granted.

Here, in recognition of National Foot Health Awareness Month in April, we’ve rounded up seven surprising health issues that you probably didn’t know were linked to your feet.

DIABETES
While Dr. Knowles says she spends much of her time performing periodic check-ups on diabetic patients who have already been diagnosed with the disease, often podiatrists can be the first to initially spot signs of the illness.

“[Patients] will come to me and say ‘Doc, I have this tingling or burning sensation in my toes’ and I’ll ask, ‘What’s your blood sugar?’” Dr. Knowles said.

Diabetes is essentially elevated blood sugar, which, according to Knowles, often affects nerves throughout the body, particularly the feet and toes.

“The [extra] sugar has to find somewhere to go. So after the sugar has taken its normal route about the body, it then starts going to places where it shouldn’t — attaching itself onto nerves,” Dr. Knowles explained. “It then deactivates those nerves and strips them of their functions. So a lot of diabetics have neuropathic pain — that’s a result of  the nerves being damaged and, therefore, not functioning well.”

HYPOTHYROIDISM/HYPERTHYROIDISM
According to the American Thyroid Association, hypothyroidism refers to an underactive thyroid gland, which can cause symptoms such as fatigue, dry skin, feeling cold and depression. Hyperthyroidism — an overactive thyroid gland — can cause nervousness; increased perspiration; thinning skin; fine, brittle hair; and muscle weakness. But, not surprisingly, early signs may also show up in the feet.

“Both of these [disorders] can cause skin changes and nail changes,” Dr. Knowles noted.

Specifically, sweaty feet can be a symptom of hyperthyroidism, while dry, cracked feet can be a sign of hypothyroidism.

NUTRITIONAL DEFICIENCIES
A range of nutritional deficiencies present themselves via symptoms in the feet, according to Knowles.

In the field of podiatry, calcium and vitamin D deficiencies — which often affect the bones — are commonly seen in patients. But Dr. Knowles said she also sees patients with numbness and nerve pain related to B-12 deficiencies as well as insufficient magnesium levels.

NEUROLOGICAL DISORDERS
Pain and other uncomfortable symptoms that show up in the feet, toes and ankles are sometimes related to neurological conditions. But the relationship between neurological disorders and the feet can be complicated, according to Dr. Knowles.

“Lower back pain can be caused by structural issues in the foot, for example,” she noted. “And, at the same time, a slipped disc in the back can cause radiating pain down the legs.”

And when it comes to kids, structural abnormalities could be an early sign of neuromuscular diseases.

RENAL FAILURE
Swollen feet and other skin changes in the lower extremities as well as nail discoloration can sometimes indicate issues with the kidneys or even renal failure, according to Knowles.

CARDIOVASCULAR DISEASES
Meanwhile, lack of hair growth on the toes can be indicative of poor circulation or atrophy of the skin. In cases of high blood pressure, swelling of the feet and ankles is also common, Dr. Knowles noted.

CANCER
According to the American Podiatric Medical Association, most skin cancers on the feet are painless, and often there is a history of recurrent cracking, bleeding or ulceration. Often, people discover their skin cancer after unrelated ailments near the affected site.

“If you see see some streaking of the nail or some black lines, it’s worth getting it checked out, because those things sometimes indicate that you have some underlying cancer,” Dr. Knowles advised. “If you notice any lesions on the feet that weren’t there before, a biopsy is never a bad idea. A lot of cancers that could eventually go to the lungs can show up as skin legions on the feet or elsewhere.”