Electric ‘zaps’ in the toe are often a sign of nerve damage, doctors say

Persistent, painful electric-shock sensations in a toe are most commonly caused by peripheral neuropathy — damage to the nerves that carry sensations between the body and the brain — and warrant assessment by a primary care clinician, doctors say.

Peripheral neuropathy can produce a range of abnormal sensations, including pins and needles, numbness, burning or intermittent sharp "zaps" that may wake patients from sleep. The condition is often chronic and can flare intermittently, leaving people sleepless and anxious when episodes recur.

Clinicians identify a number of common triggers. Diabetes is the leading cause because long-term high blood sugar can damage the small blood vessels that supply peripheral nerves, and many people with diabetes lose sensation in their feet. Certain medications — including some chemotherapy agents, some antiseizure drugs and some blood pressure medicines — have been implicated. Excessive alcohol intake, deficiency of vitamin B12 (most often seen in people who eat little or no animal products), spinal injuries, shingles and Lyme disease are other recognised causes.

Diagnosis typically begins in general practice with a clinical history and examination focused on the distribution of symptoms, associated weakness, and factors such as diabetes, medication use, alcohol intake and past infections or injuries. Blood tests can look for diabetes and vitamin B12 deficiency. In some cases, doctors will refer patients for nerve conduction studies, imaging or to neurology or pain specialists if the cause is unclear or symptoms are severe.

Treatment aims first at addressing any reversible causes. For people with diabetes, tighter blood sugar control can slow progression. Those with a documented B12 deficiency are advised to take supplements. Reducing or stopping alcohol and reviewing potentially causative medications with a doctor can also prevent further nerve injury. Where the underlying cause cannot be reversed, symptom relief can be offered; commonly prescribed options include the anticonvulsant gabapentin and the tricyclic antidepressant amitriptyline, which may reduce nerve pain. GPs can initiate these treatments and arrange further assessment where needed.

Scleroderma, a rare autoimmune disease in which the body overproduces collagen, can also cause nerve and joint problems that lead to chronic pain. Patients with scleroderma who are being considered for joint replacement surgery should be counselled about specific risks, including slower wound healing and potential breathing complications if the disease involves the lungs. Doctors recommend joint consultations between surgical and rheumatology teams, assessment of lung function and exhausting non-surgical options such as steroid injections and physiotherapy before proceeding to an operation. Patients retain the right to decline surgery if they are uncomfortable with the risk profile or recovery prospect.

For patients taking blood-thinning medication who also have diverticulitis, doctors routinely consider prescribing a proton pump inhibitor such as lansoprazole. Diverticulitis involves small pouches in the intestinal wall that can become inflamed or bleed. Blood-thinning drugs increase the risk of gastrointestinal bleeding, and lowering stomach acid with a PPI reduces that risk. Long-term PPI use has been associated in some studies with small increases in the risk of conditions such as osteoporosis-related fractures and certain infections, and observational work has suggested possible links with other outcomes; however, clinicians generally judge that the proven benefit of preventing serious bleeding in patients taking antiplatelet or anticoagulant therapy outweighs those potential long-term risks when diverticular disease is present.

Paracetamol remains widely recommended for many types of acute pain, and clinical evidence supports its short-term effectiveness when taken at recommended doses. Some observational studies have reported possible associations between long-term or high-dose paracetamol use and outcomes such as tinnitus or kidney problems, but these findings are not conclusive and causation has not been established. Doctors stress that paracetamol can be harmful in overdose and should be used according to dosing guidelines.

Public health measures around shingles vaccination have also expanded. People aged 70 to 79 are being offered two doses of the recombinant shingles vaccine Shingrix, and those who reached age 65 on or after Sept. 1, 2023, are included in routine offers. In addition, anyone aged 18 or over with a severely weakened immune system — for example because of cancer or immune-suppressing medications — is now eligible for the vaccine. Shingles results from reactivation of the chickenpox virus and can cause a painful rash and, in some cases, persistent nerve pain.

Doctors advise patients who experience recurrent or severe electric-shock sensations, new numbness, weakness, unexplained foot ulcers, or sudden changes in bladder or bowel control to seek prompt medical assessment. General practitioners can perform initial investigations, manage reversible causes and refer to specialists for further testing or treatment when necessary.

The information presented reflects general medical guidance and should not replace individualized medical advice. Patients with specific concerns or complex medical histories are encouraged to consult their own clinicians for tailored assessment and management.