Dear Sergio,
What I've experienced, seen, and read concerning physical effects of withdrawal (detoxing) off what you call heavy drugs is that 3 days is unrealistically short. The initial effects can include body aches, nausea, vomiting, headache, convulsions, visual hallucinations, rapid pulse/breathing, coma, black outs, slurred speech--depending on the drug in question--and these symptoms can last up to several weeks. The flu-like symptoms can last longer. Emotional effects, such as anxiety, depression, irritation, hyperactivity, an inability to feel a sense of joy or happiness, sleeplessness (or the reverse, chronic fatigue), nightmares, dreams about using can last a year or more, with 3 to 6 months being the most intense period. Post-acute withdrawal symptoms are recurring symptoms that can cycle around in that first year, as the body attempts to heal itself. Body chemistry rebounds--tries to balance the depletion of adrenaline (from coke)or dopamine (from heroin)due to over stimulation--and this healing process can feel like a roller coaster. There are bad, bad days, a not so bad day, then a good day, then a bad day--well, you get the idea. Up to a certain point, the body will heal, and even with a surprising degree of abuse, our bodies still try to heal, but the general idea is, it doesn't happen overnight, and it doesn't even happen over 3 nights. Youth is an advantage in some ways, but the trade-off is that the body doesn't develop or develops poorly, and the addiction process can occur in a shorter period of time. Aging means a higher risk of harm with less ability to heal. Support during this process is critical, whether that's group therapy, individual therapy (or both), and connection to friends or family or a community of people going through the same process.

blt