Always being hungry is not normal, and may be the sign of a disorder. Constant hunger, also called hyperphagia or polyphagia, can be persistent or intermittent, and may not always cause weight gain, Medline Plus says. An excess desire for food can result from a hormonal disorder, such as hyperthryroidism or diabetes; a mental condition, such as bulimia; or a hereditary disease, such as Prader-Willi syndrome or Von Gierke disease.
Prader-Willi Syndrome
Prader-Willi Syndrome is a genetic disorder that causes constant, ravenous hunger that results in life-threatening obesity in children, says the National Institute of Child Health and Human Development. A defect in the hypothalamus, the part of the brain that controls feelings of hunger and fullness, causes the person to experience constant feelings of starvation. Children with Prader-Willi syndrome will constantly seek food, and locks may have to be placed in food storage areas to prevent extreme obesity. Compounding the problem is the fact that people with the condition actually need fewer calories due to reduced muscle mass, another characteristic of the syndrome. Other symptoms include picking at the skin, low levels of sex hormones, hoarding behavior and repetitive thoughts and verbalizations.
Type 1 Diabetes
Type 1 diabetes, or insulin-dependent diabetes, is an autoimmune disorder. The immune system attacks and kills the insulin-producing cells in the pancreas. Type 1 diabetics need lifelong daily insulin injections. Insulin is a hormone your body needs to convert nutrients, such as sugars and carbohydrates, into energy. Diabetes can lead to serious health consequences, such as vision loss, kidney failure and lower limb amputations. Constant hunger is a common symptom of type 1 diabetes. People lose weight despite increased food intake. Thirst and urination increase, and vision may be blurred. The onset of type 1 diabetes is rapid, and a life-threatening condition called diabetic ketoacidosis can cause coma and death.
Von Gierke Disease
Von Gierke disease is also called type I glycogen storage disease, or GSD I. It is an inherited disease that causes low blood sugar. Von Gierke disease causes a person's body to be unable to break down glycogen to release glucose for energy, due to lack of the necessary enzyme. Besides constant hunger and the need to eat frequently, people with this condition experience nosebleeds, easy bruising, irritability, fatigue, and a thin chest and limbs, a swollen belly and puffy cheeks. Signs of stunted growth and an enlarged liver may be present. Treatment focuses on avoiding low blood sugar by eating frequently during the day, and being fed by a tube at night. Low blood sugar can be life-threatening and can damage the brain and other organs.
Hyperthyroidism
The thyroid gland produces a hormone, thyroxine, that regulates metabolism. Hyperthyroidism is a disorder that causes overproduction of thyroxine, which speeds up the metabolic rate and causes weight loss, a rapid heart rate, increased sweating, irritability, anxiety and an increased appetite. Frequent bowel movements and insomnia can also result. Hyperthyroidism can be caused by an autoimmune disorder, such as Grave's disease; hyperfunction within the thyroid gland; or inflammation that occurs with no known cause. Untreated hyperthyroidism can seriously damage the heart, says the Mayo Clinic. A life-threatening condition called thyrotoxic crisis can occur, resulting in the sudden intensification of symptoms such as a rapid pulse, delirium and a high fever.
Bulimia Nervosa
Bulimia nervosa is described as a compulsion to binge on large quantities of food and then purge with laxatives, vomiting, fasting or exercise to prevent weight gain. This cycle repeats itself, and has detrimental effects on physical and psychological health. Bulimics cannot resist the urge to binge. Afterward, people living with this condition experience shame and disgust, according to HelpGuide.org. Tension and feelings of deprivation and hunger build up as a person with bulimia tries to diet, and powerful cravings result. Signs and symptoms of bulimia include discolored teeth, scars and calluses on the knuckles, fluctuations in weight, excessive exercising, going to the bathroom right after a meal, and the use of laxatives and enemas.
References
- NYTimes.com: Personal Health--Disorder Makes Hunger a Constant Companion
- National Institute of Child Health and Human Development: Prader-Willi Syndrome
- National Diabetes Education Program: Helping the Student With Diabetes Succeed--A Guide for School Personnel
- Medline Plus: Von Gierke Disease
- Medline Plus: Increased Appetite
