Alcohol can be very dangerous when ingesting too much at once or too much over time. It can damage various organs such as the brain, the liver, or the heart; it can even damage your immune system. 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. Drinking a lot over a long time or too much a single time can damage the heart, causing problems including cardiomyopathy (stretching and drooping of heart muscle), arrhythmias (irregular heart beat), stroke, and high blood pressure. Drinking too much can also weaken your immune system, making your body a much easier target for disease. Chronic drinkers are more likely to contract diseases like pneumonia (lung infection) and tuberculosis (bacterial infection) than people who do not drink too much. Drinking a lot on a single occasion slows your body’s ability to ward off infections.