The sensation of constant hunger is a symptom of several diseases. It may occur on its own or with other symptoms and if not treated it will lead to excessive eating. This in turn will result in weight gain in most people. However, this sensation of hunger is also sometimes confused with other sensations like pain in the stomach region and even low energy levels.
Not all of the causes of constant hunger are diseases. Sometimes it can be a symptom of a physiologic change in the body, like with pregnancy. This is usually short lived. However, when constant hunger is associated with excessive weight gain or even weight loss, and other symptoms then it needs to be investigated further.
Excessive Hunger vs Excessive Eating
While we all understand that hunger is a signal for us to eat food, excessive hunger does not always mean excessive eating. Sometimes a person may feel hungry but are not able to tolerate large amounts of food or even have an appetite for a small meal. At other times we overeat without the sensation of hunger and even when feeling ‘full’ (satiety).
It is therefore important to differentiate overeating (without any hunger sensation) from excessive hunger. When hunger does not subside with eating or returns a short period of time after eating then it can referred to as abnormal and excessive. The focus of this article is on excessive or constant hunger, with or without appetite changes and eating excessively.
Read more on overeating.
How does hunger work?
Hunger centers in the brain are stimulated by various factors. A low blood glucose level will stimulate these hunger centers which then signals us that we need to eat. It may also send impulses to the stomach which churns which we refer to as hunger pangs. However, the sight, smell, taste and even thought of certain foods can also stimulate the hunger center. Similarly emotions can also have an effect on the hunger center, especially in some people.
If we do not eat, the body will utilize its nutrient stores to sustain itself. However, the hunger sensations will intensify. Once we eat, the blood glucose levels rise and the stomach distends. This sends signals to the satiety center in the brain which in turn ‘switches off’ the hunger center. The activation and deactivation of these centers are also responsible for appetite.
Read more on appetite control.
Causes of Excessive Hunger
Some of the more common causes of constant hunger have been discussed below. Most of these conditions present with other symptoms but at times excessive hunger can be the only obvious symptoms. Intestinal worm infestation is often thought to be a cause of excessive hunger how this only occurs in some cases.
This is one of the leading causes of excessive or constant hunger in developed nations as the incidence of diabetes rises, particularly with the obesity pandemic. In diabetes the body either has a shortage of the hormone insulin (type 1) or becomes unresponsive to insulin (type 2). As a result the blood glucose levels cannot be properly controlled and may rise above the normal threshold.
However, excessive hunger may also be noticed with hypoglycaemia where the blood glucose levels drop too low. The hunger sensation is stimulated and a person needs to eat to maintain the blood glucose levels within a normal range. Hypoglycemic attacks may also occur in diabetes, especially those with poorly managed cases.
Another common cause of excessive hunger in females is pregnancy. The effects of the pregnancy hormones as well as the increased nutritional demand of the developing fetus can lead to constant hunger. In addition many pregnant women experience cravings for specific foods and sometimes these foods increase appetite momentarily.
A number of upper gastrointestinal conditions can causes changes in appetite. With common conditions like gastritis and peptic ulcer disease, the dull gnawing ache and burning pain in the stomach and duodenum may mislead a person into believing that they are constantly hunger. Sometimes food eases these symptoms but only temporarily.
Psychological stress is another common cause of constant hunger. The effect of the emotional upset and stress hormones can disrupt blood glucose levels and upset appetite control. Sometime the opposite may occur where a person experiences little to no hunger and the appetite is diminished. Some people also comfort eat as a way to cope with stress which can lead to overeating.
The thyroid hormones control metabolism and this in turn influences appetite. A person with a higher metabolism requires more nutrients for energy production. While metabolic rates may differ among individuals, sometimes an overactive thyroid can lead to constant and excessive hunger. This is known as hyperthyroidism.
Mental Health Conditions
Appetite changes may occur with several types of mental health conditions, which are not eating disorders. For example some people may eat or feel hungry when anxious. An increased appetite may also be seen with depression. Often individuals who experience increased hunger with anxiety or depression find that food is a source of comfort.
Eating disorders are also mental health conditions where the symptoms often revolve around eating patterns. In conditions like bulimia a person may binge due to cravings or perceived hunger as well as using food as a source of comfort. This is followed by feelings of guilt and the need to purge (induce vomiting).
Several drugs can increase appetite or aggravate conditions like gastritis and peptic ulcers. This leads to increased hunger or other sensations may be mistaken for hunger. Drugs like anti-anxiety medication, antidepressants, antipsychotics and corticosteroids are some of the common drugs to cause increased appetite. Antibiotics and NSAIDs like aspiring may worsen the symptoms of gastritis and peptic ulcers which could be perceived as hunger.
Apart from medication, a number of other substances can also cause constant hunger for different reasons. Alcohol may cause or exacerbate gastritis and peptic ulcers. It may also impair a person’s appetite control. Illicit substances can also have a similar effects, particularly with marijuana which is known for stimulating appetite.