A metabolic disorder occurs when abnormal chemical reactions in the human body disrupt the metabolism, which is the complex set of chemical reactions that the body uses to maintain life, including energy production. When the disruption happens and there is a hormone or enzyme deficiency, the patient may have too much of some substances or too little of others, which are needed to stay healthy. A metabolic disorder can develop when some organs, such as the liver or pancreas, become diseased or do not function normally. Diabetes is one common example. Inherited metabolic disorders refer to different types of medical conditions caused by genetic defects that interfere with the body's metabolism.



Metabolic disorders cause disturbances in the normal chemical processes in the body and result in different symptoms, depending on the particular disorder. The symptoms can vary in intensity among individuals.

The symptoms of inherited metabolic disorders include:

  • Body fluids that have a maple smell;
  • Bone abnormalities such as osteoporosis;
  • Difficulty with memory, thinking, talking, comprehension, writing or reading;
  • Enlarged liver, heart, kidney or spleen;
  • Frequent infections;
  • Hypoglycemia;
  • Loss of vision or changes in vision;
  • Muscle twitching, spasms or seizures;
  • Muscle weakness;
  • Paralysis.

Symptoms of acquired metabolic disorders include:

  • Chronic or persistent diarrhea;
  • Fatigue;
  • Headache;
  • Irritability and mood changes;
  • Muscle cramping;
  • Nausea with or without vomiting;
  • Rapid breathing or shortness of breath.

In some cases, metabolic disorders can be life threatening, which may include:

  • Bluish coloration of the lips or fingernails;
  • Change in mental status or sudden behavior change, such as confusion, delirium, lethargy, hallucinations and delusions;
  • Respiratory or breathing problems, such as shortness of breath, difficulty breathing, labored breathing, wheezing, not breathing, choking;
  • Seizure.



Disorders in metabolism can be inherited, in which case they are known as inborn errors of metabolism or they may be acquired. They may also occur as complications of other serious diseases, such as liver or respiratory failure, cancer, end-stage chronic obstructive pulmonary disease and HIV/AIDS. There are numerous examples of inherited metabolic disorders, for instance:

  • Amino acid disorders;
  • Carbohydrate disorders;
  • Fatty acid oxidation defects.

Metabolic disorders can be caused by other factors, such as a combination of inherited and environmental factors, such as:

  • Alcohol abuse;
  • Diabetes;
  • Diuretic abuse;
  • Gout;
  • Ingestion of poison or toxins, including excessive aspirin, bicarbonate, alkali, ethylene glycol or methanol;
  • Kidney failure;
  • Pneumonia, respiratory failure or collapsed lung;
  • Sepsis.


Risk Factors

A number of factors increase the risk of developing metabolic disorders. Those could be:

  • Certain chronic medical conditions, such as lung or kidney disease;
  • Family history of genetic metabolic disorder;



Complications of untreated metabolic disorders can be serious, even life threatening in some cases and they may include: organ failure or dysfunction, seizures and tremors, unconsciousness and coma.