Heroin withdrawal is usually not directly life-threatening, but it can become dangerous due to complications. Severe vomiting, diarrhea, dehydration, and electrolyte imbalance can strain the body, especially in people with other medical conditions. Extreme agitation or relapse risk can also lead to overdose if heroin use resumes after tolerance drops. While uncomfortable and intense, withdrawal itself is rarely fatal, but medical supervision is recommended for safety and symptom management.