How do you know when someone is using smack?

Signs that someone may be using heroin (often referred to as "smack") can include noticeable changes in behavior, such as sudden withdrawal from social activities, extreme lethargy, or mood swings. Physical symptoms may include pinpoint pupils, a runny nose, or track marks on arms. Additionally, there may be a presence of paraphernalia like needles or burnt spoons. If you suspect someone is using, it's important to approach the situation with care and concern.