paresthesia
Meaning of paresthesia: The distribution of the tingling carries most of the information, since it maps onto whichever nerve or nerve root is affected.
Definition of paresthesia
Paresthesia is an abnormal skin sensation arising without any outside cause, described as pins and needles, tingling, prickling, crawling, burning or numbness. It reflects nerve fibers firing on their own or conducting poorly. Brief episodes after leaning on a nerve are ordinary and harmless, while persistent paresthesia points to something affecting the nerve somewhere along its course.
Why does a limb tingle?
Sustained pressure on a nerve squeezes both the fibers and their blood supply, and conduction falters. Larger fibers, which carry touch and position sense, fail first, which is why the limb feels dead before it feels anything else. When the pressure lifts, those fibers recover unevenly and fire spontaneously for a minute or two, and that disorganized barrage is felt as pins and needles. The same principle applies to longer-lasting causes: a nerve injured by compression, inflammation, poor blood supply or a metabolic disturbance generates signals that the brain can only interpret as sensation from the skin it serves.
What does the pattern indicate?
| Distribution | Where the problem usually lies |
|---|---|
| Thumb, index and middle fingers, worse at night | Median nerve compressed at the wrist |
| Little finger and half the ring finger | Ulnar nerve at the elbow |
| A stripe down the arm or leg | A single nerve root pinched at the spine |
| Both feet symmetrically, creeping upward | A generalized peripheral neuropathy |
| One side of the body, sudden onset | A central cause within the brain or spinal cord |
What are the related terms?
Paresthesia is neutral in tone. Dysesthesia describes an abnormal sensation that is unpleasant or painful, allodynia describes pain provoked by something that should not hurt such as light touch, and hypoesthesia describes reduced sensation. Recording which of these applies matters, because they arise from different fiber types. A neurologic assessment adds the questions the sensation alone cannot answer: how quickly it began, whether it is constant, whether muscle weakness or loss of reflexes accompanies it, and whether the pattern fits a single nerve, a root, or a widespread process such as diabetes, vitamin B12 deficiency, thyroid disease or a drug effect.
Used in a sentence
The patient reported paresthesia in the fingers after leaning on the elbow.
Good to know
The location, timing, triggers and any accompanying weakness are what narrow the possible causes, since the sensation itself feels much the same whatever produces it.
Word origin
Where “paresthesia” comes from
Formed from Greek para-, meaning beside or abnormal, combined with aisthesis, meaning sensation.