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Long-term effects of an eating disorder

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, 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; baggy skin caused by rapid weight loss; bruising; stretch marks caused by rapid weight gain; wrinkles; calluses on your hands (from using your fingers to make yourself vomit); irritation at the corners of your mouth; growth of a downy body hair called lanugo; dry brittle hair; hair loss; and blue skin caused by a lack of oxygen (known as cyanosis).

Heart and circulation

Your heart and circulation can suffer in many ways: a slowed or irregular heart beat, which can make your heart stop; heart failure; dizziness when standing because of low blood pressure; low body temperature and coldness caused by poor circulation; fluid retention causing puffiness and weight gain; weeing a lot; low blood glucose (sugar) causing dizziness and shaking; irritability; 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 (such as your heart, brain and kidneys) working well. Purging, through vomiting, using laxatives, or dieting, leads to low levels of potassium, chloride and sodium. This may cause weakness, tiredness, muscle pain, depression, and 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, reflux, and dehydration that leads to constipation. Using laxatives can cause loss of bowel function (you cannot control when you poo), irritable bowel syndrome, stomach cramps, and bloating. Starvation can cause malnutrition and you may stop being able to tell when you're hungry. All eating disorders can lead to you no longer being able to know when you're full.


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

Hormones and sexuality

If you're 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 properly 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 doesn't work well; have difficulty sleeping and be tired from too much exercise; lose bone density (osteoporosis), meaning you're more likely to break bones; and lose muscle.

Psychological effects

Attitude to food

As well as having distorted attitudes to food, eating, and body shape and size, parents with eating disorders may pass on their attitudes and beliefs about food to children.

Attitude to other things

People with eating disorders often lose interest in other activities, and motivation in general. 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, poor school and work performance, and a constant feeling of being watched by other people when you're eating.

People with eating disorders often spend large amounts of money on binge foods, diet foods, 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, but may include having your children put into foster care if your disorder is affecting your ability to parent, and being subject to compulsory treatment under the Mental Health Act 1992.

Written by the South Island Eating Disorders Service, Canterbury DHB. Adapted by HealthInfo clinical advisers. Last reviewed January 2021.


Page reference: 73639

Review key: HIEDI-73561