Causes of Polyphagia

Polyphagia, also known as hyperphagia, is an intense hunger that is not satiated by eating. The craving can be for food in general, or a specific food, and leads to overeating. It is a symptom associated with several conditions, primarily diabetes.

Diabetes

Diabetes is a group of metabolic disorders that affect the way the body processes and uses sugar.

Left untreated, diabetes causes blood glucose (sugar) to rise to harmful levels and can cause damage to organs or lead to organ failure and death.

The three main types of diabetes are:

• Type 1: This is an autoimmune disease that cannot be prevented. With type 1 diabetes, the pancreas makes no insulin or very little insulin. This type almost always requires the administration of insulin via injections or a pump that sits on the skin.
• Type 2: The hallmark of this type of diabetes is insulin resistance, in which the body cells don't respond normally to insulin. Over time, the pancreas can't make enough insulin to compensate for the resistance, and blood glucose rises.
• Gestational: Gestational diabetes is diabetes that develops during pregnancy and usually goes away after the birth of the baby. Untreated, it can cause pregnancy complications.

Polyphagia is one of the "three Ps" of diabetes, along with:

• Polyuria: Increased urination
• Polydipsia: Increased thirst

These three symptoms are some of the most recognizable symptoms of diabetes.

Other symptoms of diabetes include:

• Nighttime urination
• Unexplained weight loss
• Blurry vision
• Numbness or tingling in hands or feet
• Fatigue
• Dry skin
• Increased infections
• Sores, bruises, wounds, and infections that are slow to heal

Symptoms of type 1 diabetes can also include:

• Nausea
• Vomiting
• Stomach pains

Gestational diabetes often has no symptoms. People who are pregnant should be screened for gestational diabetes between 24 and 28 weeks of pregnancy, or more often if indicated by their healthcare provider.

Poor Blood Sugar Levels

Too much or too little sugar in the blood can trigger polyphagia. This happens most frequently with people who are diabetic and can be an indication that the diabetes is not properly managed.

Hyperglycemia

Hyperglycemia means there is too much sugar in the blood.

Body cells need insulin in order to use blood sugar for energy. Insulin needs vary based on the type of diabetes:

• People with type 1 diabetes do not make any insulin or make a very small amount of insulin.
• People with type 2 diabetes have insulin resistance.

Both of these prevent the cells from being able to access the blood sugar and use it efficiently.

Because the cells are not getting the energy from the food being eaten, the body still sends out hunger signals. Eating more food then raises the blood sugar higher, creating a cause and effect cycle.

Other symptoms of hyperglycemia include:

• Blurred vision
• Frequent urination
• Headache
• Fatigue
• Unexplained weight loss
• Infections (vaginal and skin)
• Wounds, cuts, bruises, and infections that are slow to heal

If not addressed, hyperglycemia can lead to ketoacidosis (a buildup of ketones in the blood, causing toxicity), primarily in people with type 1 diabetes.

Symptoms of ketoacidosis include:

• Vomiting
• Dehydration
• Sweet or fruity breath
• Sweet-smelling urine
• Difficulty breathing or hyperventilation
• Confusion or disorientation
• Rapid heartbeat
• Coma

Hypoglycemia

Hypoglycemia refers to low blood sugar and can also cause polyphagia.

With hypoglycemia, the body sends hunger signals because the cells are not receiving sugar from the blood to use for energy. This is because there is not enough sugar in the blood for the cells to use.

Hypoglycemia is a common occurrence for people with type 1 diabetes and diabetics who are taking insulin or diabetes medication. An excess of insulin lowers blood sugar too much.

It can also be caused by:

• Not eating enough food
• The types of foods eaten (for instance, too few carbohydrates)
• Miscalculated timing or amount of insulin injected
• Physical activity

These can throw off the balance between insulin and blood sugar.

Other symptoms of hypoglycemia include:

• Hunger
• Nausea
• Feeling shaky
• Sweating, chills, or clamminess
• Feeling nervous or anxious
• Confusion
• Fast heartbeat
• Irritability or impatience
• Pallor (color drained from the skin)
• Sleepiness
• Feeling weak/no energy
• Headache
• Blurred/impaired vision
• Problems with coordination/clumsiness
• Tingling or numbness in the lips, tongue, or cheeks
• Nightmares or crying out during sleep (blood sugar often drops at night)
• Seizures

Symptoms of severe hypoglycemia include:

• Blurred vision
• Difficulty concentrating
• Confused thinking
• Slurred speech
• Numbness
• Drowsiness
• Falling unconscious
• Seizures

Hyperthyroidism 

Hyperthyroidism occurs when the thyroid gland (a small gland in the front of the neck) produces too many thyroid hormones. Untreated, this can cause:

• Heart problems
• Problems with bones and muscles
• Menstrual cycle abnormalities
• Fertility problems
• Pregnancy complications (for parent and baby)

The increased metabolism (the process of turning food into energy) resulting from hyperthyroidism can cause an increased appetite or polyphagia.

Other symptoms of hyperthyroidism include:

• Palpitations (rapid heartbeat)
• Feeling shaky, nervous, or anxious
• Muscle weakness
• Weight loss
• Digestive problems (diarrhea and more frequent bowel movements)
• Thin skin
• Menstrual changes
• Sleep problems
• Double vision
• Intolerance to heat
• Excessive sweating
• Swelling and enlargement of the neck from an enlarged thyroid gland (goiter)
• Hair loss
• Change in hair texture (brittle)
• Bulging of the eyes (seen with Graves’ disease)

People with type 1 diabetes are among those at an increased risk for hyperthyroidism.

Premenstrual Syndrome (PMS)

Premenstrual syndrome (PMS) is a collection of physical, psychological, and emotional symptoms experienced by some people during the one to two weeks before a menstrual period.

An increased appetite and food cravings (especially for sweet or salty foods) are symptoms of PMS.

Other symptoms include:

• Bloating
• Breast tenderness
• Acne
• Swelling of feet and ankles
• Headaches
• Fluid retention and weight gain
• Uterine cramps just before and during the first few days of menstruation
• Fatigue/low energy
• Back or muscle pain
• Palpitations
• Dizziness
• Emotional changes such as mood swings, irritability, depression, aggressiveness or hostility, crying spells
• Difficulty concentrating
• Forgetfulness
• Changes in sex drive

Sleep Disruptions

Proper sleep is important, especially for people with conditions such as diabetes. Sleep disturbances can throw blood sugar levels off balance.

Lack of Sleep

While a restless night or two isn't usually harmful, longer-term lack of sleep can cause problems with blood sugar, which in turn can increase instances of polyphagia.

Inadequate sleep increases hormones such as cortisol and adrenaline, which can make the body less sensitive to insulin. This triggers an increase in glucose (blood sugar), which can lead to hyperglycemia.

In addition to hyperglycemia, polyphagia from lack of sleep can be caused by increased hunger to compensate for exhaustion.

Fluctuating blood sugar can also make getting adequate, uninterrupted sleep difficult for people who are diabetic.

Sleep Apnea

Obstructive sleep apnea is characterized by long pauses (more than 10 seconds) in breathing during sleep. It is common in people who have diabetes and/or people who are overweight.

Symptoms of sleep apnea include:

• Frequent snoring
• Constantly feeling sleep-deprived/falling asleep during normal daytime activities
• Difficulties with learning, concentrating, and memory
• Disturbed sleep
• Depression
• Irritability
• Sexual dysfunction

If left untreated, sleep apnea can lead to:

• Daytime exhaustion and fogginess
• Drowsy driving
• High blood pressure
• Cardiac problems such as arrhythmia, congestive heart failure, heart attack
• Stroke
• Depression and mood issues
• Memory issues
• Insulin resistance, which can increase the risk of type 2 diabetes

As with lack of sleep, the sleep disturbances associated with sleep apnea can lead to blood sugar imbalances that increase instances of polyphagia.

Stress, Anxiety, or Depression

Stress, anxiety, and depression can affect lives in many ways, including self-care. Experiencing these stressors can make things like eating well, exercising, and getting enough sleep more difficult, which can cause health problems (such as uncontrolled blood sugar).

Stress and mental health problems also make the management of diabetes less consistent and increase stress hormones such as cortisol, which are known to increase blood sugar.

Uncontrolled blood sugar from stress, anxiety, or depression can lead to polyphagia.

Feeling anxious, depressed, or stressed can also increase comfort-eating and binge-eating. While comfort-eating and binge-eating are not the same as polyphagia, they can cause increased blood sugar, which leads to polyphagia.

Symptoms of stress include:

• Nervousness
• Fast heartbeat
• Rapid breathing
• Digestive problems
• Depression

Symptoms of depression include:

• Feeling sad
• Irritability
• Loss of interest in activities
• Feeling worthless
• Changes in sleep
• Fatigue or low energy

Rare Medical Conditions

Some medical conditions can cause polyphagia, including two rare disorders.

Kleine-Levin Syndrome

Primarily affecting adolescent males (though it can affect anyone), Kleine-Levin syndrome is a disorder marked by episodes lasting a few days to a few weeks.

During these episodes, people with Kleine-Levin syndrome can experience:

• Excessive sleep (up to 20 hours a day)
• Polyphagia
• Flu-like symptoms
• Irritability
• Childishness
• Disorientation
• Hallucinations
• Abnormally uninhibited sex drive

Between episodes, these symptoms disappear. People with Kleine-Levin syndrome may not remember everything that happened during the episode.

The exact cause of Kleine-Levin syndrome is unknown, but it may be due to a malfunction of the hypothalamus and thalamus (parts of the brain that control appetite and sleep).

Prader-Willi Syndrome

Prader-Willi syndrome is a genetic condition present at birth and marked by the onset of polyphagia beginning in early childhood.

In infancy, the symptoms of Prader-Willi syndrome include:

• Hypotonia (weak muscle tone)
• Feeding difficulties
• Poor growth
• Delayed development

Other characteristics of Prader-Willi syndrome include:

• Mild to moderate intellectual impairment and learning disabilities
• Behavioral problems including temper outbursts and stubbornness
• Compulsive behavior such as skin picking
• Sleep abnormalities
• Distinctive facial features such as a narrow forehead, almond-shaped eyes, and a triangular mouth
• Short stature
• Small hands and feet
• Underdeveloped genitals
• Delayed or incomplete puberty
• Infertility (usually)

Many people with Prader-Willi syndrome become overweight, and some develop type 2 diabetes.

Side Effects of Medication

Some medications can cause polyphagia, including:

• Corticosteroids: This includes cortisone, prednisone, and methylprednisolone.
• Cyproheptadine: An antihistamine.
• Tricyclic antidepressants: This includes Anafranil (clomipramine), Ascendin (amoxapine), and Elavil (amitriptyline).

Polyphagia can also be a result of marijuana use.

A Word From Verywell

Polyphagia can be caused by a number of different conditions, and can often be treated.

Treatment for polyphagia depends on the underlying condition—for example, diabetes-related hyperphagia is managed by keeping blood sugar levels balanced and under control.

If you are experiencing symptoms of hyperphagia, make an appointment with your healthcare provider to discuss the next steps.