When people become addicted to substances, they exhibit compulsive behavior. In this state, people lose control of limiting exposure to the substance which can make them even more addicted by using too much. Substances are addictive because they fulfill a reward system in our brain. However even after the actual need for the drug passes, this reward system still wants to be satisfied and when people choose to do so they begin to become addicted to using the substance.
When substance use is abruptly halted and withdrawal symptoms occur, then there is physical dependence to the drug. However, even if a person is dependent on a drug, it does not necessarily mean they are also addicted. A person that suffers from intense pain due to an injury needing treatment, may choose to use a pain killer drug in order to ease the pain. If they stopped using the pain killer, but the wound was not treated yet, they would experience pain and would want to use the drug. However, once the wound is treated and there is no longer any more pain, if they still want to use the drug then they would be addicted to the drug rather than just depending on it to relieve temporary pain.
As someone uses drugs more frequently, their body will adapt to the dose and in order to reach previous effects, increased dosages will need to be applied. The original dose loses its earlier effects. As with dependence, having higher tolerance towards a drug does not necessarily mean that the person is also addicted to the drug. The human body will naturally adjust as different substances enter the body. For instance, when morphine enters the body, it binds to opiate receptors and prevents certain enzymes from doing their jobs which would make the morphine to leave the receptor. This allows the morphine to make the person feel better as it is still with the receptor. However, over time the enzyme will adapt and be able to perform its duties without being disabled by the morphine which in turn requires more morphine to enter the body in recurring times.
When people stop using drugs after having used them for a while, they will experience the opposite effects that the drug had on them. These effects or symptoms can vary from moderately unpleasant to life-threatening. If a person can overcome the period of withdrawal and abstain from using more drugs, they will become more likely to overcome addictions they may have.
The excessive use of alcohol or other drugs. By doing so, you become at risk for physical, emotional and social problems that may grow to concern the lives of those around you in addition to your own livelihood.