Plain English Meaning
An odd skin feeling — tingling, prickling, or pins-and-needles — that happens on its own, without anything actually touching the skin. At altitude, it can be an early warning sign of decompression sickness.
Full Definition
An abnormal skin sensation — typically tingling, prickling, burning, or a 'pins and needles' feeling — occurring without an external physical cause. In the context of altitude-induced decompression sickness (DCS), paresthesia results from nitrogen bubbles forming in tissues or pressing on nerves as ambient pressure drops.
Context Anchor
Seen in altitude-induced decompression sickness discussions, especially in symptom lists for pilots operating at high altitude or after a rapid loss of cabin pressure.
Derivation
From Greek 'para-' meaning 'beside' or 'abnormal,' and 'aisthesis' meaning 'sensation.' Literally 'an abnormal sensation' — a feeling that shouldn't be there.