You've run for decades, put hundreds of miles on your body. And one day, your feet hurt so bad you can't do it any more. It may be a case of peripheral neuropathy.
A painful condition, peripheral neuropathy is caused by damage to your peripheral nervous system and can kick it at any age. Each minute of your life, your peripheral nerves are sending and receiving messages from the central nervous system (your brain and spinal cord). When these nerves are damaged, communication between your brain and the rest of your body is interrupted, causing severe pain that activities such as running may become impossible.
Nerve damage is a common occurrence with a long list of possible causes. Diabetes (high blood sugar levels for a long period of time) and shingles (a.k.a. post herpetic neuralgia in the medical world)) are the two most common triggers for peripheral neuropathy. Other medical issues that may lead to neuropathy include vitamin deficiencies (especially B12 and folate); autoimmune diseases such as lupus, rheumatoid arthritis, or AIDS; liver infections; kidney disease; or an underactive thyroid.
Other risk factors include exposure to certain toxins such as gold compounds, lead, mercury, arsenic, pesticides, and heavy metals. Heavy alcohol use, as well as certain drugs that treat cancer, high blood pressure, infections, or seizures may also result nerve damage.
As if the list weren't long enough, your neuropathy can be worsened by poor blood flow to your legs, a bone fracture or other traumatic injury, overexposure to cold temperatures, carpal tunnel syndrome, or simply the repetitive pounding your feet take when you're out running.
While every runner's experience with peripheral neuropathy is different, there are common signs and symptoms of this condition. Initially, you may feel tingling, numbness, abnormal sensations, or pain in your feet. Over time, this feeling may spread to your legs and hands.
The neuropathy may come on gradually over a period of years or suddenly. Over time, your neuropathy may lead to a loss of coordination, muscle weakness, a feeling of heaviness in your extremities, loss of balance, difficulty walking, or even a lack of bowel or bladder control. As you continue to live with your running-induced neuropathy, the tingling feelings may become painful and cause sharp, deep stabbing sensations that are often worse at night. Severe cases of peripheral neuropathy may be so debilitating that you're required to use a wheelchair.
There are two main goals in the treatment of peripheral neuropathy. The first is to determine and treat the cause. If it is brought on by uncontrolled diabetes, gaining control will help. If it is brought on by a vitamin deficiency, you may be prescribed supplements.
The second goal of treatment is to manage the painful symptoms of neuropathy. This is usually done with the use of medications. If over-the-counter pain medications aren't sufficient, prescription painkillers, anti-seizure medications, or antidepressants may be prescribed. When these don't help, electrical nerve stimulation therapies may help, and surgical intervention is available when nothing else does the trick.
Doctors once ordered patients with peripheral neuropathy to abstain from all exercise. Yes, frequent running may cause neuropathy symptoms to flare up, and if the pain becomes severe enough, running may be completely out of the question. However, research has found that activities such as running may actually help alleviate and prevent nerve damage, since it improves your circulation, increases the amount of oxygen in your body, and strengthens nerve tissue. But you've got to run right.
If you have peripheral neuropathy and can't stop running, be sure to start slowly, include an adequate warm up to your routine, and stay sensitive to any pain or numbness in your feet. Wear supportive shoes and if needed, leg splints or braces. Massaging your feet after a run may also help relieve post-running pain. And when you're not running, don't cross your legs or keep heavy objects on your lap for long periods of time.