How long can a tick live under the skin in a human? - briefly
A feeding tick can stay attached for roughly 5 to 14 days, most species detaching after about a week. After this interval the parasite typically dies or is expelled by the host.
How long can a tick live under the skin in a human? - in detail
A tick that has attached to a person remains viable only while it can obtain a blood meal. The feeding period varies by species and developmental stage.
- Larvae and nymphs (soft‑tick families): typical attachment lasts 12–14 days. After this interval the tick either molts to the next stage or dies if it cannot detach.
- Adult hard ticks (Ixodidae): engorgement may require 5–10 days, with some species extending up to 14 days under optimal conditions. The tick’s metabolism slows once the blood volume is sufficient, and it will detach to lay eggs or seek a new host.
- Extreme cases: laboratory observations report survival of up to 21 days when the host’s skin remains intact and the tick is not disturbed, but such durations are rare in natural human infections.
Physiological constraints limit prolonged residence. A tick’s salivary glands produce anticoagulants and immunomodulators for the first few days; after the blood meal is complete, the glandular activity declines, and the insect becomes immobilized. Host immune responses, tissue inflammation, and loss of moisture eventually cause death if detachment does not occur.
Consequences of extended embedding include higher probability of pathogen transmission. For most tick‑borne bacteria and viruses, transmission risk rises sharply after 24–48 hours of attachment, reaching maximal levels near the end of the feeding period.
Prompt removal within the first 24 hours shortens exposure to blood‑borne agents and prevents the tick from reaching the engorgement stage that would allow it to survive for several additional days. After removal, the tick usually dies within hours to a few days, depending on its species and the amount of blood it has ingested.