Which health problems are associated with excessive alcohol use?

Several. You are at higher risk for liver disease. In addition, chronic alcohol users have a higher risk for stroke, heart disease, and some cancers. Alcohol is a toxin and kills brain cells which can never regenerate. Alcoholics are also at higher risk for diabetes and accidents of all kinds.
Everything. Alcohol has toxic effects on the brain and nervous system, the heart, the liver, the gastrointestinal tract, the pancreas, muscle and virtually every human organ system. It causes dementia, cirrhosis, pancreatitis, diabetes, gastritis, neuropathy, myopathy. The greatest problems are on the person's function and relationships with others, often changing personality, causing depression and anxiety.