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Long-term effects of an eating disorder

Ngā pānga karioi o te matenga kainga

Eating disorders can cause many changes to the way your body works. Being undernourished affects your organs, blood, skin, hair and bones. Binge eating, vomiting, abusing purgatives, dieting and too much exercise have many health effects. These can be both physical and psychological. They also have social and legal consequences.

Physical effects

Skin and hair

Changes to your skin and hair can include skin breakdown and poor healing, dry skin and baggy skin caused by rapid weight loss. They can include bruising, stretch marks caused by rapid weight gain and wrinkles. Changes can include calluses on your hands (from using your fingers to make yourself vomit). Other changes can include irritation at the corners of your mouth and growth of a downy body hair called lanugo. Also, dry brittle hair, hair loss and blue skin caused by a lack of oxygen (cyanosis).

Heart and circulation

Your heart and circulation can suffer in many ways. These include heart failure or a slowed or irregular heartbeat, which can make your heart stop. They can include dizziness when standing because of low blood pressure. Also, low body temperature and coldness caused by poor circulation. They can include fluid retention causing puffiness and weight gain and weeing a lot. They can also include low blood glucose (sugar) causing dizziness and shaking. Also, irritability and tiredness caused by anaemia (too few red blood cells).

Electrolyte disturbances

Electrolytes are minerals in your blood and body fluids. They affect the amount of water in your blood. You need to have the right balance in your blood to keep your organs (heart, brain and kidneys) working well. Vomiting, using laxatives or dieting, leads to low levels of potassium, chloride and sodium. This may cause weakness, tiredness, muscle pain and depression. It can also cause broken blood vessels under your eyes. Serious electrolyte disturbances can cause seizures, and your heart may actually stop.

Dental problems

The gastric acid from vomiting can strip away your tooth enamel and cause tooth decay and mouth ulcers.

Gastrointestinal problems

Frequent vomiting can cause tears in your oesophagus and stomach. It can also cause reflux and dehydration leading to constipation. Using laxatives can cause loss of bowel function (you cannot control when you poo). It can also include irritable bowel syndrome, stomach cramps and bloating. Starvation can cause malnutrition and you may stop being able to tell when you are hungry. All eating disorders can lead to you no longer being able to know when you are full.


Using diuretics and laxatives can cause dehydration. This can lead to intense thirst, decreased weeing, swelling and puffiness and headaches. Dehydration can also cause dizziness and fainting, chronic fatigue and confusion. Also, increased body temperature, kidney failure and in severe cases, death.

Hormones and sexuality

If you are malnourished, it can affect your hormone levels. Women's periods can become irregular or stop altogether. Men's testosterone levels may fall. Women who are vomiting or have diarrhoea may not absorb oral contraceptives and may become pregnant. You may lose interest in sex or become sexually impulsive.

Other problems

You may get more infections because your immune system does not work well. You may have difficulty sleeping and be tired from too much exercise. You may also lose muscle and bone density (osteoporosis). This means you are more likely to break bones.

Psychological effects

Attitude to food

People with eating disorders have distorted attitudes to food, eating, body shape and size. Parents with eating disorders may pass on their attitudes and beliefs about food to their children.

Attitude to other things

People with eating disorders often lose motivation and interest in other activities. They often develop depression.

Social, legal, and financial effects

An eating disorder affects the way a person behaves around other people. It can lead to isolation, secrecy, mistrust and poor school and work performance. It can also lead to a constant feeling of being watched by other people when you are eating.

People with eating disorders often spend large amounts of money on binge foods and diet foods. Also, doctor's appointments and gym memberships. They also frequently take a lot of time off work. The legal consequences can vary from person to person. They may include having your children put into foster care if your disorder affects your ability to parent. It may also include being subject to compulsory treatment under the Mental Health Act 1992.

Written by the South Island Eating Disorders Service. Adapted by HealthInfo clinical advisers. Last reviewed March 2024.


Page reference: 73639

Review key: HIEDI-73561