Physical effects of anorexia

Naomi Carr
Author: Naomi Carr Medical Reviewer: Morgan Blair Last updated:

Anorexia nervosa is an eating disorder characterized by restrictive eating patterns and a preoccupation with one’s body shape and/or size. The restrictive eating patterns result in excessive weight loss or prevention of weight gain. If left untreated, anorexia can cause serious and potentially fatal medical complications. Professional treatment is recommended to treat this mental health disorder.

Early-onset and short-term physical effects of anorexia

In the early stages of anorexia, certain physical changes and effects can occur quickly due to malnutrition and low levels of electrolytes. Many of these effects can be treated or reversed with appropriate medical intervention and nutrition, but left untreated, the effects could cause permanent health issues [1].

Some of the early-onset and potentially short-term effects of anorexia include [2][3]:

  • Excessive fatigue
  • Cognitive impairments, such as difficulty concentrating
  • Weight and muscle loss
  • Decline in heart rate and blood pressure
  • Feeling very cold, particularly cold hands and feet
  • Hair loss
  • Dry skin and hair
  • Growth of fine hair over the body and face
  • Constipation, stomach pain, and bloating
  • Missed, delayed, or stopped menstrual periods in females

Serious and long-term physical effects of anorexia

If anorexia is untreated or continues for a long period of time, physical effects can worsen, and severe medical complications can occur. Some of these complications can be treated and managed, but some may lead to long-term or permanent issues, such as organ failure, or death [4][5].

These health risks may be higher in those who experience anorexia in adolescence and whose condition is left untreated. Anorexia can cause delays or impairments in the ability for the body to develop properly and can cause irreversible harm to certain areas of the body [6][7].


Malnutrition can lead to loss of gray and white matter in the brain, which can cause impairments in cognitive functioning. Generally, brain matter returns following treatment and refeeding. Although there may continue to be a reduction in the amount of gray matter in the brain, leading to long-term cognitive impairments [3][6].

Neurotransmitters, such as dopamine and serotonin, which impact mood and information processing, have been found to be altered in those with chronic or long-term anorexia. This can cause severe changes in mental state, including depression, obsessive-compulsive thoughts and behaviors, and anxiety, and impact decision-making abilities [8].

Hormonal and reproductive systems

Many females with anorexia experience a loss of menstruation due to malnutrition [1]. While it is likely for periods to return following treatment, long-term or untreated anorexia can lead to severe hormonal abnormalities and result in a permanent loss of periods and infertility. Anorexia has also been linked to issues in pregnancy, such as poor fetal growth and birth complications [5][7][9].

Similarly, males with anorexia often experience hormonal deficiencies such as reduced levels of testosterone, which can also have a long-term impact on fertility [10].


Hormonal and nutritional deficiencies can also impact bone health, potentially causing a permanent loss of bone density and strength. A decrease in bone density can lead a condition called osteopenia, which is the precursor to an irreversible condition called osteoporosis. Osteoporosis is characterized by bone weakness, which can lead to chronic fractures. This occurs in a high proportion of those with anorexia [3][10].

Anorexia that occurs during adolescence can have a serious impact on the health and growth of bones, potentially causing stunted growth and significantly increasing the risk of bone fractures throughout the individual’s lifetime [6][10].


Cardiac changes that occur with anorexia, such as low blood pressure and slow heart rate, can return to normal after treatment and recovery.

However, malnourishment and low electrolyte levels can cause several serious cardiac issues, some of which can be permanent or even fatal. This includes atrophy of the heart muscles, which leads to poor heart functioning, and irregular heartbeats. These conditions can lead to sudden cardiac arrest or heart failure [3][6].

Cardiac problems are very common amongst those with anorexia and can lead to sudden and unexpected complications, contributing to a high proportion of the fatalities that occur with anorexia [5][11].


Anorexia can also have severe or fatal effects on the lungs. This includes pneumonia, weakened and damaged lungs, breathing complications, and complete respiratory failure. Anorexia that persists long term or is untreated significantly increases the risk of physical effects on the lungs [6][10].


Poor nutritional intake can also impact the level of oxygen in the blood and lead to poor blood health, such as anemia and leukopenia (low red and white blood cells). This can contribute to fatigue and weakness, an increased risk of illness and slower recovery time, and slower wound healing [6][10].

What to do if you notice these symptoms in someone

If you notice any of the above physical effects in someone you know, you should try to encourage them to seek professional help. These symptoms can be indicative of an eating disorder, they may receive a diagnosis and appropriate treatment for anorexia. Alternatively, there may be other causes or conditions happening that require medical intervention and treatment.

Sometimes, people with anorexia nervosa struggle to seek professional help due to an intense fear of having to increase their food intake and gain body weight. As a loved one, you could offer to go with them to see their doctor for added support. If they are reluctant, you may wish to speak to a medical professional yourself for advice on how to help them receive appropriate medical intervention [1].

Although this can be a challenging and distressing process, it is important that anorexia is treated as soon as possible, to prevent mental and physical health deterioration and severe or fatal medical complications [12].

Treatment options for anorexia

Anorexia is best treated with professional intervention, so if you or someone you know has anorexia, it is advised to seek professional help as soon as possible to prevent a worsening of symptoms or physical complications.

Treatment for anorexia involves a multidisciplinary approach, typically involving a physician, dietician, specialized therapist, and psychiatrist, who can work collaboratively to treat all the physical and mental aspects of the condition [1][12].

The medical doctor will work to treat any physical health complications that have occurred. The dietitian will work to increase a person’s nutritional intake and provide education around body health and eating habits. The therapist will work with the individual to manage emotional distress, and explore the underlying causes of their illness, which can help to promote more balanced thoughts and behaviors around eating [1][13].

In some cases, medications can be prescribed to help reduce certain symptoms of anorexia. This will depend on the condition of the individual’s physical and mental health and if a doctor deems it appropriate, as there can be an increased risk of side effects in malnourished individuals [1]. If medication is recommended, a psychiatrist will work to find the medication and dose that is right for the individual.

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  3. Sidiropoulos, M. (2007). Anorexia Nervosa: The Physiological Consequences of Starvation and the Need for Primary Prevention Efforts. McGill Journal of Medicine: MJM: An International Forum for the Advancement of Medical Sciences by Students, 10(1), 20–25. Retrieved from
  4. National Eating Disorders Association. (2022). Health Consequences. NEDA. Retrieved from
  5. Meczekalski, B., Podfigurna-Stopa, A., & Katulski, K. (2013). Long-Term Consequences of Anorexia Nervosa. Maturitas, 75(3), 215-220. Retrieved from
  6. Mehler, P.S., & Brown, C. (2015). Anorexia Nervosa – Medical Complications. Journal of Eating Disorders, 3, 11. Retrieved from
  7. O’Brien, K.M., Whelan, D.R., Sandler, D.P., Hall, J.E., & Weinberg, C.R. (2017). Predictors and Long-Term Health Outcomes of Eating Disorders. PloS one, 12(7), e0181104. Retrieved from
  8. Speciani, M., Barak, Y., Damanhuri, H., De Ronchi, D., Panariello, F., & Atti, A. R. (2021). A Perspective on Chronic and Long-Lasting Anorexia Nervosa. Frontiers in Psychiatry, 12, 756669. Retrieved from
  9. Kimmel, M.C., Ferguson, E.H., Zerwas, S., Bulik, C.M., & Meltzer-Brody, S. (2015). Obstetric and Gynecologic Problems Associated with Eating Disorders. International Journal of Eating Disorders, 49(3), 260-275. Retrieved from
  10. Puckett, L., Grayeb, D., Khatri, V., Cass, K., & Mehler, P. (2021). A Comprehensive Review of Complications and New Findings Associated with Anorexia Nervosa. Journal of Clinical Medicine, 10(12), 2555. Retrieved from
  11. Jáuregui-Garrido, B., & Jáuregui-Lobera, I. (2012). Sudden Death in Eating Disorders. Vascular Health and Risk Management, 8, 91–98. Retrieved from
  12. Jones, M., & Brown, T. (2022). Why Early Intervention for Eating Disorders is Essential. NEDA. Retrieved from
  13. National Health Service. (Reviewed 2021). Treatment – Anorexia. NHS. Retrieved from
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Naomi Carr
Author Naomi Carr Writer

Naomi Carr is a writer with a background in English Literature from Oxford Brookes University.

Published: May 9th 2023, Last edited: Sep 22nd 2023

Morgan Blair
Medical Reviewer Morgan Blair MA, LPCC

Morgan Blair is a licensed therapist, writer and medical reviewer, holding a master’s degree in clinical mental health counseling from Northwestern University.

Content reviewed by a medical professional. Last reviewed: May 9th 2023