Here’s how alcohol can affect your body:
Brain:
Alcohol interferes with the brain’s communication pathways, and can affect the way the brain looks and works. These disruptions can change mood and behavior, and make it harder to think clearly and move with coordination. 
Heart:
Drinking a lot over a long time or too much on a single occasion can damage the heart, causing problems including:
Cardiomyopathy – Stretching and drooping of heart muscle
Arrhythmias – Irregular heart beat
Stroke
High blood pressure 
Research also shows that drinking moderate amounts of alcohol may protect healthy adults from developing coronary heart disease.
Liver:
Heavy drinking takes a toll on the liver, and can lead to a variety of problems and liver inflammations including:
Cancer:
Drinking too much alcohol can increase your risk of developing certain cancers, including cancers of the:
Immune System:
Drinking too much can weaken your immune system, making your body a much easier target for disease