Alcohol's Effects on the Body

Drinking too much – on a single occasion or over time – can take a serious toll on your health. The whole body is affected by alcohol use--not just the liver, but also the brain, gut, pancreas, lungs, cardiovascular system, immune system, and more.

Current research points to health risks even at low amounts of alcohol consumption, regardless of beverage type. Keep reading for more information on how alcohol can affect your body.

Brain/Neurological 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 alcohol can also increase the risk of stroke. More information about alcohol’s effects on the brain is available on NIAAA’s topic page on Alcohol and The Brain.

In addition to its effects on the brain, alcohol also affects the peripheral nervous system, which comprises the nerves outside the brain and spinal cord. For example, alcohol misuse is linked to peripheral neuropathy, a condition that commonly occurs in people with severe alcohol use disorder (AUD) and can cause numbness in the arms and legs and painful burning in the feet. Alcohol-related damage to nerves may also cause heart arrythmias (irregular heartbeat), postural or orthostatic hypotension (a drop in blood pressure due to a change in body position), diarrhea, and erectile dysfunction.

Endocrine System

Heavy alcohol use can disturb the endocrine system, disrupting the hormones that help maintain the body’s stability and health. Because these disturbances permeate every organ and tissue in the body, they can contribute to endocrine-related health conditions including thyroid diseases, dyslipidemia (abnormal cholesterol levels in the blood), reproductive dysfunction, and stress intolerance, and diabetes. There is also evidence that alcohol can disrupt or delay puberty.

In patients with diabetes, any alcohol intake may reduce their ability to control blood glucose levels adequately and contribute to diabetes-associated cardiovascular and neurologic complications. Furthermore, heavy drinking may increase the risk for developing type 2 diabetes due to increased body weight, blood triglyceride levels, or blood pressure, and decreased insulin sensitivity, for example.

Gastrointestinal System and Oral Cavity

Drinking alcohol can contribute to a ‘leaky gut’ allowing the intestines to permit substances like toxins into the body, which can change the composition of the microbiota or microorganisms living in the gastrointestinal (GI) tract, and increase the risk of colorectal cancer (see Cancer section below for more detail). Alcohol can damage the epithelial lining of the GI tract, promote inflammation within and beyond the GI system, and cause GI bleeding. Alcohol is also associated with an increased risk of gastroesophageal reflux disease. And drinking is associated with an increased risk of esophageal cancer and oral cavity cancer. (See below Cancer section for more information.)

Heart and Circulatory System

Alcohol misuse can damage the heart. Research has demonstrated that long-term heavy drinking weakens the heart muscle, causing cardiomyopathy. Alcohol misuse can also lead to high blood pressure, an irregular heartbeat (arrhythmia), or increased heart rate. Chronic, heavy drinking raises the risk for ischemic heart disease (heart problems caused by narrowed arteries) and myocardial infarction (heart attack). Even low drinking levels may confer risk. Heavy alcohol use can cause deficiencies in specific components of the blood, including anemia (low red blood cell levels), leukopenia (low white blood cell levels), thrombocytopenia (low platelet levels), and macrocytosis (enlarged red blood cells).

Immune System

Drinking too much alcohol can weaken the immune system, making the body a much easier target for disease. Drinking a lot on a single occasion slows the body’s ability to ward off infections–even up to 24 hours later. Both acute and chronic heavy use of alcohol can interfere with multiple aspects of the immune response, the result of which can impair the body’s defense against infection, impede recovery from tissue injury, cause inflammation, and contribute to alcohol-related organ damage.

Alcohol can affect behaviors that increase the likelihood of acquiring or transmitting HIV to others. Alcohol may also speed HIV progression in people living with the disease, influence their engagement and retention in HIV treatment, and increase their susceptibility to organ damage and coinfections.

Liver

Heavy drinking takes a toll on the liver, and can lead to a variety of problems and liver inflammations including:

Alcohol-associated steatosis
Alcohol-associated steatohepatitis
Alcohol-associated hepatitis
Alcohol-associated fibrosis
Alcohol-associated cirrhosis
Hepatocellular carcinoma

Lungs

Alcohol misuse is associated with an increased risk of acute respiratory distress syndrome, bacterial pneumonia, and respiratory syncytial virus infection. People who drink often are more liable to contract diseases like pneumonia and tuberculosis than people who do not drink too much.

Musculoskeletal System

Drinking increases the risk of myopathy or muscle wasting. Heavy alcohol use raises the risk for fractures and even low levels of alcohol intake increase the odds for recurrent gout attacks. Alcohol also impairs bone fracture repair and reduces bone density.

Pancreas

The pancreas is an organ that makes substances that support bodily functions including digestion and metabolism. Alcohol misuse over time can lead to pancreatitis, which can impair the production of digestive enzymes and can affect hormones that regulate blood sugar level.

Pancreatitis is a dangerous inflammation in the pancreas that causes it to swell and become painful. The pain from pancreatitis may spread.

Pancreatitis can occur as a sudden attack, called acute pancreatitis. Acute pancreatitis can turn into chronic pancreatitis, which is a condition of constant inflammation of the pancreas. Chronic pancreatitis is a risk factor for the development of pancreatic cancer and diabetes.

Cancer

According to the National Cancer Institute (NCI): "There is a strong scientific consensus that alcohol drinking can cause several types of cancer. In its Report on Carcinogens, the National Toxicology Program of the U.S. Department of Health and Human Services lists consumption of alcoholic beverages as a known human carcinogen. The evidence indicates that the more alcohol a person drinks–particularly the more alcohol a person drinks regularly over time–the higher his or her risk of developing an alcohol-associated cancer. Even those who have no more than one drink per day and people who binge drink (those who consume 4 or more drinks for women and 5 or more drinks for men in one sitting) have a modestly increased risk of some cancers.”

Clear patterns have emerged between alcohol consumption and increased risks of certain types of cancer:

Head and neck cancer, including oral cavity, pharynx, and larynx cancers.
Esophageal cancer, particularly esophageal squamous cell carcinoma. In addition, people who inherit a deficiency in an enzyme that metabolizes alcohol have been found to have substantially increased risks of esophageal squamous cell carcinoma if they consume alcohol.
Liver cancer.
Breast cancer: Research has shown an important association between alcohol consumption and breast cancer—even one drink per day can increase a woman's risk for breast cancer by 5% to 15% compared to women who do not drink at all.
Colorectal cancer.

For more information about alcohol and cancer, please visit the National Cancer Institute's webpage "Alcohol and Cancer Risk" (last accessed June 6, 2024).