my father is 43 and has a history of abusing many drugs, heroin the most. he had been clean for about five years, until MAYBE recently. he became disabled two years ago after getting diagnosed with a rare bone disease and many surgeries followed making him worse and worse. his pain is bad but he has too much to loose! recently family members are approaching me to stay away and not follow his foot steps. i’m with him A LOT i’m only 18 but i haven’t seen anything wrong. he has a boil on vein of his arm. quarter like shaped, right where you’d put an IV. he said it was from a spider, i don’t know. he last used when i was small enough to be clueless so i’m taking the word of my family that the signs have risen again. what are some signs and symptoms of a user? please HELP.