Complications

Alcohol depresses your central nervous system. In some people, the initial reaction may be stimulation. But as you continue to drink, you become sedated.

Too much alcohol affects your speech, muscle coordination and vital centers of your brain. A heavy drinking binge may even cause a life-threatening coma or death. This is of particular concern when you're taking certain medications that also depress the brain's function.

Impact on your safety

Excessive drinking can reduce your judgment skills and lower inhibitions, leading to poor choices and dangerous situations or behaviors, including:

• Motor vehicle accidents and other types of accidental injury, such as drowning
• Relationship problems
• Poor performance at work or school
• Increased likelihood of committing violent crimes or being the victim of a crime
• Legal problems or problems with employment or finances
• Problems with other substance use
• Engaging in risky, unprotected sex, or experiencing sexual abuse or date rape
• Increased risk of attempted or completed suicide

Impact on your health

Drinking too much alcohol on a single occasion or over time can cause health problems, including:

• Liver disease. Heavy drinking can cause increased fat in the liver (hepatic steatosis), inflammation of the liver (alcoholic hepatitis), and over time, irreversible destruction and scarring of liver tissue (cirrhosis).
• Digestive problems. Heavy drinking can result in inflammation of the stomach lining (gastritis), as well as stomach and esophageal ulcers. It can also interfere with absorption of B vitamins and other nutrients. Heavy drinking can damage your pancreas or lead to inflammation of the pancreas (pancreatitis).
• Heart problems. Excessive drinking can lead to high blood pressure and increases your risk of an enlarged heart, heart failure or stroke. Even a single binge can cause a serious heart arrhythmia called atrial fibrillation.
• Diabetes complications. Alcohol interferes with the release of glucose from your liver and can increase the risk of low blood sugar (hypoglycemia). This is dangerous if you have diabetes and are already taking insulin to lower your blood sugar level.
• Sexual function and menstruation issues. Excessive drinking can cause erectile dysfunction in men. In women, it can interrupt menstruation. 
• Eye problems. Over time, heavy drinking can cause involuntary rapid eye movement (nystagmus) as well as weakness and paralysis of your eye muscles due to a deficiency of vitamin B-1 (thiamin). A thiamin deficiency can also be associated with other brain changes, such as irreversible dementia, if not promptly treated.
• Birth defects. Alcohol use during pregnancy may cause miscarriage. It may also cause fetal alcohol syndrome, resulting in giving birth to a child who has physical and developmental problems that last a lifetime.
• Bone damage. Alcohol may interfere with the production of new bone. This bone loss can lead to thinning bones (osteoporosis) and an increased risk of fractures. Alcohol can also damage bone marrow, which makes blood cells. This can cause a low platelet count, which may result in bruising and bleeding.
• Neurological complications. Excessive drinking can affect your nervous system, causing numbness and pain in your hands and feet, disordered thinking, dementia, and short-term memory loss.
• Weakened immune system. Excessive alcohol use can make it harder for your body to resist disease, increasing your risk of various illnesses, especially pneumonia.
• Increased risk of cancer. Long-term, excessive alcohol use has been linked to a higher risk of many cancers, including mouth, throat, liver, esophagus, colon and breast cancers. Even moderate drinking can increase the risk of breast cancer.
• Medication and alcohol interactions. Some medications interact with alcohol, increasing its toxic effects. Drinking while taking these medications can either increase or decrease their effectiveness, or make them dangerous.