Begin Your Recovery
(619) 797-7319

How Does Addiction Work in the Body and Brain?

CALL NOW: (619) 797-7319

How Does Addiction Work in the Body and Brain?

Written by Genesis Recovery

Every year, addiction affects millions of Americans. Like any other disease, addiction wreaks havoc on the brain and the body. Whether we’ve struggled with addiction on our own or watched a loved one or close friend grapple with substance use, most of us know that addiction changes the way the brain works and negatively impacts the body. But the average American probably doesn’t know how addiction works. In many ways, addiction masquerades as a desirable friend, when in fact, this “friend” secretly causes you pain.

How Does Addiction Happen?

Addiction begins with desire. Some people use addictive substances to escape emotional, psychological, or physical pain, while others use drugs and alcohol to relax or cope with family, school, financial, and career pressure. Other reasons for substance use include boredom, a need for instant gratification, a desire for rebellion, peer pressure, curiosity, or a need to feel in control. All of these reasons are rooted in desire. Drugs and alcohol seem to satisfy users’ desire by evoking the brain’s pleasure center.

When addictive substances enter the bloodstream and travel to the brain, they come in contact with the part of the brain that signals reward and elicits pleasure. The brain registers all types of pleasure the same way, whether they come from a drug, alcohol, monetary reward, sex, or an appetizing meal. The brain does this by releasing dopamine. Addictive substances shortcut the brain’s reward system by flooding the brain with dopamine. The hippocampus, which regulates memory, memorizes this rapid sense of satisfaction, triggering the amygdala, an almond-shaped gland, to respond to pleasurable stimuli. Unfortunately, dopamine doesn’t just evoke pleasurable feelings, the neurotransmitter also helps regulate learning and memory. Essentially, dopamine and the hippocampus teach the brain to not only seek out addictive substances but to want them consistently and compulsively. The brain holds on to this memory. When the sought-after substance becomes less pleasurable, the brain demands more, unintentionally initiating the cycle of addiction.

How Addiction Affects the Brain

Once addictive substances hijack the brain’s reward center, they start to alter the brain’s neural connections, change the organ’s structure, and negatively impact how the mind functions.

Addiction Alters How Neurons in the Brain Communicate

Addictive substances interfere with the way neurons, or nerve cells in the brain, send, receive, and process signals via chemical messengers called neurotransmitters. Drugs like marijuana and heroin activate neurons because their chemical structure mimics the structure of neurotransmitters. But they don’t activate neurons in the same way, which causes abnormal messages in the brain network. Amphetamine and cocaine can cause neurons to release excessive amounts of naturally-occurring neurotransmitters, also disrupting normal communication between neurons. Alcohol and opioids work in a similar way. Miscommunication between neurons disrupts the balance of neurotransmitters, which can cause depression, insomnia, oversleeping, restlessness, irritability, paranoia, and severe fatigue.

Addiction Changes the Structure of the Brain

Drugs also affect the brain by shrinking or enlarging specific parts of the organ. Research consistently shows that drugs and alcohol can decrease volume in the prefrontal cortex, which helps us plan, think, solve problems, make decisions, and exert self-control over our impulses. In contrast, addictive substances enlarge the basal ganglia, which is associated with habits, routines, learning, and emotion. When damaged, the basal ganglia can cause involuntary movements, muscle spasms, problems finding words, and tremors. Drugs and alcohol can also increase sensitivity in the amygdala, making substance users highly vulnerable to anxiety, irritability, and other distressing feelings associated with drug and alcohol withdrawal.

Addiction Negatively Impacts How The Brain Functions

Brain scans also show that drugs and alcohol can cause abnormal levels of brain activity, particularly in the prefrontal cortex, which regulates decision making. Researchers believe this may be part of the reason why people grappling with addiction challenges frequently engage in risky behaviors.

How Addiction Affects the Body

The brain isn’t the only part of the body affected by addiction. Drugs and alcohol can negatively impact vital systems in the body and alter the way essential organs function.

Internal Effects of Addiction on the Body

As drugs and alcohol travel through the bloodstream, toxic chemicals begin to affect major organs in the body such as the heart, liver, kidney, and lungs. Toxins from addictive substances build up in the organs, causing chronic issues such as cancer, heart diseases, and liver and kidney failure. Drugs and alcohol are also commonly associated with high blood pressure, infertility, and an irregular heartbeat. Inhalants can cause blackouts, hearing loss, and bone-marrow damage, while cocaine is commonly associated with stroke, heart attacks, and an increased vulnerability to infection. If addiction doesn’t cause organ damage, using addictive substances can weaken the immune system, making alcoholics and drug users more prone to diseases, viruses, and bacterial infections.

External Effects of Addiction on the Body

As addiction wreaks havoc on the internal body, physical changes can occur. Using drugs and alcohol can cause extreme weight loss, sudden weight gain, acne, and skin lesions. Tobacco and nicotine prematurely age the skin. Methamphetamine can cause severe tooth decay and gum disease also known as meth mouth. Prolonged use of drugs and alcohol can also lead to baldness or male pattern hair growth in women.

Helping You Overcome Addiction from the Inside Out

Here at Genesis Recovery, we know that addiction is a disease that causes both internal and external damage. We also know that addiction is treatable. Our comprehensive treatment approach can help you rehabilitate your life from the inside out. We combine clinical support with the 12-step program to help you overcome addiction challenges and change your habits for the better. But we also offer holisticly-nurturing activities and a supportive community that can help you transform your life from the inside as well.

Addiction challenges don’t have to continue to control your life. You can begin again and we can help you get there. Contact us today at 619-797-7319 if you, a loved one, or a close friend are struggling with addiction.

We're Here To Help.
Contact Us Today.


(619) 797-7319


[email protected]


24352 Featherstone Canyon Rd, Lakeside, CA 92040
[email protected]