Some signs of addiction include impaired speech, dilated pupils, disrupted sleep patterns, inability to deal with stress and legal problems. Drug addiction is a complex disease that takes more than good intentions and strong will to quit, notes the National Institute on Drug Abuse.
Individuals who are addicted to substance use are not able to control their urge to take more. They continue using the substance even when it causes bodily harm, states Mayo Clinic. Continued use of substance often leads to mental and physical health, the law and finances.
One of the early signs of substance addiction is missing important engagements. The individual's work or school attendance may become irregular due to staying out late or getting intoxicated at odd hours.
Addiction often leads the individual to engage in conversations that are related to getting high. This may make other people uncomfortable, which is why the addict may have to change friends. Addiction leads to sudden change of interest and hobbies. The individual is likely to become more secretive about his whereabouts.
Other signs of addiction include unexplained loss of weight, poor hygiene, irritability, change in eating habits, red eyes, foul smell, defensiveness and an uncontrollable craving for substance use. Treatment of addiction often takes the form of detoxification, counseling and self-help groups.