Numbness, tingling or “pins and needles” in an arm or a leg alongside neck or back pain usually means a nerve root is irritated where it leaves the spine, most often by a disc. It is common, it usually improves, and it is rarely an emergency. A few patterns are urgent, and they come first on this page.
Numbness around the genitals, buttocks or inner thighs; new difficulty passing urine or loss of bladder or bowel control; weakness or numbness in both legs; sudden weakness of an arm or leg, facial drooping or difficulty speaking. The last group can be a stroke: call emergency services.
What the pattern can mean
Each nerve root supplies a fairly typical area of skin. Clinicians use the pattern to work out which level is involved:
| Where you feel it | Often linked to |
|---|---|
| Back of the thigh and calf, top of the foot, big toe | A lower back nerve root (L5) |
| Back of the calf, sole or outer edge of the foot | A lower back nerve root (S1) |
| Front of the thigh | A higher lumbar root |
| Thumb and index finger | A neck nerve root (C6), or the median nerve at the wrist |
| Middle finger | A neck nerve root (C7) |
| Little finger | A neck nerve root (C8), or the ulnar nerve at the elbow |
These maps overlap between people, and nerves can also be compressed away from the spine, at the wrist or elbow for example. They are a guide for a clinician, not a self-diagnosis.
Common causes
- A disc pressing on a nerve root: in the lower back this is sciatica, in the neck it causes arm symptoms. Disc material often shrinks over months, and people usually improve much sooner.1
- Narrowing of the spinal canal in older adults, often with leg symptoms on walking that ease when sitting; see spinal stenosis.
- Pressure on a nerve elsewhere, such as carpal tunnel at the wrist.
- Causes outside the spine: diabetes, vitamin B12 deficiency and some medicines can cause numbness in both feet or hands.
What usually helps
- Stay active within comfort; long sitting often aggravates leg symptoms.
- Most nerve root symptoms settle with time and non-surgical care.
- Several drugs often used for nerve pain are not recommended by NICE for sciatica.2
When to see a clinician
Soon if numbness is spreading, comes with weakness (tripping over the foot, dropping things), or has not improved after a few weeks. Urgently for any sign in the box at the top. More in red flags.
Footnotes
General information, not medical advice. Every claim carries its source; where the evidence is thin, the page says so.Editorial policy · How we grade evidence · All sources · Disclaimer