These autonomic symptoms — often appearing together — are among the earliest signs of opioid withdrawal, sometimes showing up before more obvious symptoms.
Why it happens: Opioids affect the part of the nervous system that regulates body temperature and sweating. Withdrawal produces a rebound in this system, causing alternating sweating and chills, and goosebumps (the origin of the phrase “kicking the habit cold turkey” — the skin’s appearance during this symptom).
What tends to help: Layered clothing you can add or remove easily; staying hydrated to offset fluid loss from sweating; a cool room if hot flashes are prominent.
Timing: Usually among the first symptoms to appear, often within the first 24 hours, and typically resolving within the acute withdrawal window (5–7 days for shorter-acting opioids, longer for methadone).
Medically reviewed by [pending]. Source: SAMHSA TIP 63.