Content warning: suicidality, premature death
Anorexia Nervosa (AN) is more than a struggle with food or body image, it’s a serious medical illness that affects nearly every organ system. When someone restricts calories over weeks, months, or years, the body adapts in ways that can cause lasting damage and, in some cases, become life-threatening. This article lays out the major complications of restrictive eating/anorexia in clear language so you, or someone you care about, can recognize risks and seek help early.
If you’re concerned about immediate safety (suicidal thoughts, fainting, chest pain, severe weakness, or not keeping down fluids/food), we highly recommend you seek emergency help or call your local crisis line right away.
Risk & Mortality
It’s first important to first note that there are varying amounts of severity with each eating disorder, but that it’s important to seek help early to avoid more severe outcomes. People with anorexia have a substantially increased risk of premature death compared with others, from both medical complications of malnutrition and suicide ideality. Because malnutrition affects so many systems, the illness carries one of the highest mortality rates of psychiatric disorders. Prompt treatment, especially for adolescents, can be essential to avoid long-term complications.
Now let’s break it down the health risks one by one:
Cardiovascular risks:
- Bradycardia (slow heart rate) and hypotension are common as the body reduces metabolic demand
- Arrhythmias (irregular heart rhythms) can result from low electrolytes and structural changes to the heart and may be fatal.
- Heart failure or sudden cardiac arrest can occur in severe, prolonged malnutrition.
- Monitoring pulse, blood pressure, ECGs, and electrolytes is essential during refeeding and in severe cases.
Metabolic & electrolyte problems:
- Electrolyte disturbances (low potassium, phosphate, magnesium) are common and cause weakness, breathing problems, seizures, and heart rhythm problems.
- Refeeding syndrome: rapid introduction of calories after prolonged starvation can precipitate life-threatening shifts in fluids and electrolytes. Your medical team will make sure to refeed slowly in order to avoid risk of
Bone & endocrine effects (can be long term):
- Low bone mineral density / osteoporosis: Loss of estrogen (from amenorrhea), low weight, and hormonal changes impair bone accrual. In adolescents, failure to reach peak bone mass can cause fractures and permanently reduced bone strength. Some bone loss may not fully reverse even after recovery.
- Amenorrhea and disrupted reproductive hormones are common; fertility and menstrual cycles often recover with weight restoration, but prolonged amenorrhea increases long-term bone risk.
Gastrointestinal & nutritional problems:
- Delayed gastric emptying (gastroparesis), bloating, constipation, and abdominal pain are common with severe restriction.
- Chronic inadequate intake leads to vitamin and mineral deficiencies (e.g., vitamin D, B12, iron) that cause anemia, fatigue, neuropathy, and immune weakness.
Neurological & cognitive effects:
- Malnutrition impairs concentration, memory, decision making, and planning. Over time, the brain can shrink. Many cognitive problems improve with refeeding, but recovery can be slow.
Dermatologic, dental, and peripheral effects:
- Dry, brittle hair; thinning of hair; dry skin; cold intolerance; lanugo (fine body hair).
- If purging behaviors are present, dental erosion, gum disease, and chronic sore throat may occur.
Hematologic & immune system:
- Malnutrition can cause anemia, low white blood cell counts, and reduced ability to fight infection. Some lab abnormalities reverse with nutrition; others require medical treatment.
Psychiatric risks:
- Depression, anxiety disorders, obsessive-compulsive traits, and substance use are frequently comorbid.
- Suicide accounts for a sizable fraction of deaths in anorexia; rates of suicide attempts and completed suicide are higher than in the general population. These are among the reasons early assessment and integrated psychiatric care matter.
We know that it can feel overwhelming if you or a loved one are struggling with anorexia nervosa, or any other restrictive eating disorder. However there is hope within treatment and intentional behavior change. Let’s go over which of these complications can be reversible.
Some complications (electrolyte problems, bradycardia, many cognitive and GI symptoms) often improve with careful refeeding and treatment. But some harms may be long-lasting or partially irreversible, including loss of peak bone mass in adolescents and chronic cardiac abnormalities in extreme, prolonged cases. Early treatment gives the best chance to reverse damage.
Warning signs that medical help is needed now:
We highly recommend seeking urgent care if you are experiencing any of the following:
- Fainting, dizziness, chest pain, shortness of breath, or very slow heartbeat.
- Severe weakness, inability to keep down fluids/food, or confusion.
- Suicidal thoughts or plans.
If you’re not sure if you are experiencing anorexia nervosa, contact your primary care provider or an eating disorder specialist. We also have providers here who specialize in eating disorders and call help guide you to the correct level of care.
Our team at Rooted Path specializes in eating disorder treatment and would be honored to guide you. Get started with us »
If you or someone you know is struggling with binge eating disorder, please reach out for professional support. Our team of weight-neutral practitioners is here to help guide you toward healing that honors both your body and your wellbeing.