Diagnosing Foot Neuropathy

Diagnosing peripheral neuropathy begins with a careful clinical exam and history, followed by targeted testing to confirm nerve damage and identify the underlying cause. Common tests include nerve conduction studies (NCS), electromyography (EMG), blood tests, and sometimes skin biopsy for small fiber neuropathy.

Key Takeaways

  • Diagnosis usually starts with primary care, then a referral to a neurologist.
  • Nerve conduction studies and EMG measure how well nerves transmit signals.
  • Blood tests look for diabetes, vitamin deficiency, thyroid issues, and more.
  • Skin biopsy is the gold standard for small fiber neuropathy.
  • Identifying the cause guides treatment and may reverse the condition.

Frequently Asked Questions

How is foot neuropathy diagnosed?
Diagnosis usually starts with a clinical exam by a primary care provider, who checks reflexes, vibration sense, light touch, and temperature sensation. Confirmation typically involves nerve conduction studies (NCS) and electromyography (EMG), plus targeted blood tests to look for an underlying cause. Skin biopsy may be used to confirm small fiber neuropathy.
What is a nerve conduction study?
A nerve conduction study (NCS) measures how fast and how strongly electrical signals travel along your peripheral nerves. Small electrodes deliver a brief, mild electrical pulse and record the response. The test takes 30–60 minutes and feels like a series of quick tapping sensations.
What is EMG and is it painful?
Electromyography (EMG) uses a thin needle electrode to record the electrical activity of muscles at rest and during contraction. It identifies whether weakness comes from nerve or muscle problems. Most people describe it as briefly uncomfortable rather than painful. EMG and NCS are usually performed together.
What blood tests check for neuropathy causes?
Common tests include fasting glucose and HbA1c (diabetes), vitamin B12 and methylmalonic acid, complete blood count, comprehensive metabolic panel (kidney and liver), thyroid function, and serum protein electrophoresis. Additional autoimmune, infectious, or genetic testing may be ordered based on the clinical picture.
When is a skin biopsy used?
Skin biopsy is the gold-standard test for small fiber neuropathy, in which standard nerve conduction studies are usually normal. A small punch biopsy from the lower leg is examined for the density of small nerve fibers. Reduced fiber density confirms the diagnosis.