Tests and diagnosisBy Mayo Clinic staff
Peripheral neuropathy isn't a single disease, but rather a symptom with many potential causes. For that reason it can be difficult to diagnose. Your doctor will need to determine where the nerve damage is and what's causing it.
Diagnosis usually requires:
- A full medical history. Your doctor will review your medical history, including your symptoms, your lifestyle, exposure to toxins, drinking habits and a family history of nervous system (neurological) diseases.
- Neurological examination. Your doctor may check your tendon reflexes, your muscle strength and tone, your ability to feel certain sensations, and your posture and coordination.
- Physical examination. Your doctor will likely conduct a physical examination.
Your doctor may order tests, including:
- Blood tests. You may have blood tests to measure vitamin and blood sugar levels. Blood tests may also check bodily functions, such as thyroid, liver and kidney function.
- Imaging tests. Your doctor may request imaging tests, such as a computerized tomography scan or magnetic resonance imaging, to look for herniated disks, tumors or other abnormalities.
Nerve function tests. You may have nerve function tests during your evaluation. Electromyography, a type of nerve function test, records electrical activity in your muscles to determine if your weakness is caused by muscle damage or nerve damage.
You also may have nerve conduction studies, which assess how your nerves and muscles respond to small electrical stimuli. In a nerve conduction study, a probe sends electrical signals to a nerve, and an electrode placed along the nerve's pathway records the nerve's response to the signals.
- Nerve biopsy. Your doctor may recommend this procedure to try to determine what's damaged your nerves. In a nerve biopsy, a doctor removes a small portion of a nerve and examines it for abnormalities.
- Skin biopsy. You sometimes may have a skin biopsy, in which your doctor removes a small portion of skin to examine the nerve endings for signs of abnormalities.
- Lumbar puncture. Doctors may conduct a lumbar puncture (spinal tap) to examine your cerebrospinal fluid for signs of diseases that may be causing peripheral neuropathy.
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