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What Is Hypoglycemia? What Causes Hypoglycemia?

Main Category: Diabetes
Also Included In: Nutrition / Diet | Endocrinology | Blood / Hematology
Article Date: 09 Oct 2009

A person with abnormally low levels of blood sugar (glucose) has hypoglycemia. Glucose is the body's main energy source. Hypoglycemia is not a disease in itself; it is a sign of a health problem.

The majority of people know when their blood sugar levels have dropped, and have time to do something about it. The typical signs of low sugar levels are hunger, trembling, shakiness, nausea, pallor, and sweating. Hypoglycemia is commonly linked with diabetes. Many other conditions can cause low blood sugar in people who do not have diabetes.

According to Medilexicon's medical dictionary, hypoglycemia is "Symptoms resulting from low blood glucose (normal glucose range 60-100 mg/dL [3.3-5.6 mmol/L]), which are either autonomic or neuroglycopenic. Autonomic symptoms include sweating, trembling, feelings of warmth, anxiety, and nausea. Neuroglycopenic symptoms include feelings of dizziness, confusion, tiredness, difficulty speaking, headache, and inability to concentrate."

What are the signs and symptoms of hypoglycemia?

A symptom is something the patient feels or reports, while a sign is something other people, including a doctor, may detect. For example, a headache may be a symptom, while a rash may be a sign.

Early signs and symptoms of mild hypoglycemia usually include:

Hunger
Tremor (trembling/shakiness)
Sweating
Anxiety
Irritability
Pallor (face goes pale)
Heart palpitations
Accelerated heart rate
Tingling lips

The brain needs a continuous supply of glucose to function. The brain neither stores nor manufactures glucose.

When the hypoglycemia is more severe the following signs or symptoms are possible:

Concentration problems
Confusion
Irrational and disorderly behavior (similar to somebody who is drunk)
Seizures (uncommon)
Loss of consciousness (uncommon)

The signs and symptoms that are linked to hypoglycemia may be caused by other illnesses or conditions. The only way to be sure it is hypoglycemia is with a blood test.

What are the causes of hypoglycemia?

Hypoglycemia can occur for several different reasons. It most commonly happens when a person with diabetes has taken too much insulin.

How does blood-sugar regulation occur?

The digestive system breaks down the carbohydrates from the food we eat into different sugar molecules, one of which is glucose - the body's main source of energy. Glucose goes straight into the bloodstream after we eat. However, glucose needs insulin - a hormone produced and excreted by the pancreas - before it can enter a cell. In other words, a cell would starve of energy if there were no insulin around, regardless of how much glucose there were.

After eating, the pancreas automatically releases an adequate quantity of insulin to move the glucose present in our blood into the cells, and lowers the blood sugar level. Any surplus glucose goes into the liver and muscles in the form of glycogen (stored glucose).

Insulin is responsible for bringing excess blood glucose levels back to normal.

If glucose levels have dropped because an individual has not eaten for a while, the pancreas secretes glucagon - another hormone - which triggers the breakdown of stored glycogen into glucose, which is released into the bloodstream, thus bringing glucose levels back up.

Why are people with diabetes susceptible to hypoglycemia?

People with diabetes type 1 do not produce insulin, while those with diabetes type 2 have cells which do not respond properly to insulin - they both tend to suffer from rising blood-glucose levels and cells which do not get enough energy. People with both types of diabetes need to take insulin, as well as other drugs, in order to bring their blood sugar levels down.

If a person with diabetes takes too much insulin, his/her blood sugar levels can drop too low - he/she has hypoglycemia.

A person who takes insulin may take in the normal amount for that time of day, but has eaten much less than usual, or done exercise - meaning that his/her insulin requirement for that moment is lower than usual. In other words, taking too much insulin does not necessarily mean that the patient increased the dosage; it just means that the insulin taken in was excessive for the body's needs at that moment.

Hypoglycemia causes not linked to diabetes may include:

Some medications - if somebody who does not have diabetes swallows diabetes medication they may develop hypoglycemia. Quinine, a drug used for patients with malaria, can also cause hypoglycemia. Salicylates, which are used for treating rheumatic disease, and propronanolol for hypertension (high blood pressure may also trigger a serious drop in blood sugar levels.

Alcohol abuse - the liver can stop releasing stored glucose into the bloodstream if somebody has been drinking a lot.

Some liver diseases - drug-induced hepatitis can cause hypoglycemia.

Kidney disorders - people with kidney disorders may have problems excreting medications, which can result in abnormally low blood-sugar levels.

Not eating enough - people with eating disorders, such as anorexia nervosa, may find that their blood sugar levels drop dramatically.

Insulinoma - this is a tumor in the pancreas which can make the pancreas produce too much insulin.

Endocrine problems - some disorders of the adrenal and pituitary glands can lead to hypoglycemia. Children with these disorders are more likely to develop abnormally low blood sugar levels than adults.

Reactive hypoglycemia (postprandial hypoglycemia) - this is when the pancreas produces too much insulin after a meal.

Tumors - tumors in other parts of the body (not the pancreas) can cause hypoglycemia. This is very rare.

How is hypoglycemia diagnosed?

Anybody who has a hypoglycemic attack and does not know why should see a doctor as soon as possible. The GP (general practitioner, primary care physician) will probably order a blood test to measure blood sugar levels. The doctor will also ask about symptoms, and whether they improve after the hypoglycemia has been corrected (after blood sugar levels return back to normal). The doctor will need to check the patient's medical history, whether he/she has been taking any medications, and whether there have been any recent bouts of heavy drinking.

Whipple's Triad

This is a collection of three criteria - known as Whipple's criteria - that suggest an individual's signs and symptoms are caused by hypoglycemia. The three criteria basically are:

That the signs and symptoms are known or likely to be caused by hypoglycemia. Some patients may not show signs and symptoms during their initial doctor's visit. If this is the case the patient may be asked to fast for a specified period, usually overnight. This allows hypoglycemia to occur so that a diagnosis can be made. Some patients may have to be hospitalized and undergo a longer period of fasting. If the patient exhibits symptoms after having something to eat, blood glucose levels will need to be tested after eating.

At the time of symptoms a blood test showed low plasma glucose levels.

When glucose is raised to normal levels symptoms go away.

What are the treatment options for hypoglycemia?

Hypoglycemia has two possible treatment approaches:

Immediate treatment - treating the abnormally low blood sugar attack (hypoglycemia)

Treating the underlying cause

A patient with abnormally low blood sugar needs to eat or drink something with sugar as soon as possible to end the hypoglycemia attack. Examples for rapid results include some glucose tablets, sugar lumps, sweets, or a glass of fruit juice. This should be followed by slower-release carbohydrates, such as cereals, bread, rice, or fruit.

If you suffer from diabetes, after you have checked your blood glucose and treated the hypoglycemia wait between 15 to 20 minutes and check your blood glucose again. If your blood glucose is still low repeat the whole process - eat some glucose, wait about 15-20 minutes and check your blood glucose again. Remember to stick to your eating times - your regular meals and snacks are vital for keeping your blood glucose levels as stable as possible. Hypoglycemia can affect all the organs in your body, especially your brain.

If the hypoglycemia symptoms are severe and the individual cannot treat himself/herself, somebody else will need to apply honey, treacle, jam or Glucogel to the inside of the cheeks and then gently massage the outside of the cheeks.

The sufferer should start feeling better within ten to twenty minutes.

Losing consciousness

If the patient loses consciousness they should be placed into the recovery position and administered a glucagon injection - this should be done ideally by a qualified health care provider, or somebody who knows what to do. If this is not possible the patient must be taken to an emergency department of a hospital urgently. Another option is to call for an ambulance.

If the patient has lost consciousness do not place solids or liquids (food or drink) into their mouths.

Recurrent hyperglycemia

Recurrent hyperglycemia often has an underlying cause (condition) that needs to be treated. If a medication is the cause, the doctor will recommend either another drug, or a different dosage. If a tumor is the cause, surgery will normally be needed to remove it. If the patient has Nesidioblastosis, part of the pancreas will be surgically removed.

Preventing hypoglycemia

Checking blood glucose levels - this involves keeping a regular check on blood sugar levels and knowing how to identify the onset of symptoms.

Eat regularly - keep to your eating routine.

Alcohol - a heavy drinking session can trigger hypoglycemia; so avoid them. If you have diabetes type 1 keep to within the daily alcohol limits recommended by your doctor, and eat something after you have had a drink.

Exercise - make sure you have eaten some carbohydrate-rich food before you do any exercise.

Be ready - children with diabetes type 1 should always carry a container of sugary fruit juice or a candy bar so that they are ready if symptoms are felt.

Let people know - if you are susceptible to attacks of hypoglycemia, let your friends, colleagues and family members know. Explain to them what the signs are and what should be done.

ID - if you have diabetes carry an ID form. If anything happens to you, health care providers, emergency services, and others will know what to do sooner.

In short:

If you have diabetes, follow your diabetes management plan carefully.

If you don't have diabetes but episodes of hypoglycemia recur, eat small quantities of food frequently throughout your waking hours.

Written by Christian Nordqvist
Copyright: MediLexicon International Ltd

Original article posted on Medical News Today.
Articles not to be reproduced without permission of Medical News Today

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