The most effective means of preventing further episodes of hypoglycemia depends on the cause.

The risk of further episodes of diabetic hypoglycemia can often (but not always) be reduced by lowering the dose of insulin or other medications, or by more meticulous attention to blood sugar balance during unusual hours, higher levels of exercise, or decreasing alcohol intake.

Many of the inborn errors of metabolism require avoidance or shortening of fasting intervals, or extra carbohydrates. For the more severe disorders, such as type 1 glycogen storage disease, this may be supplied in the form of cornstarch every few hours or by continuous gastric infusion.

Several treatments are used for hyperinsulinemic hypoglycemia, depending on the exact form and severity. Some forms of congenital hyperinsulinism respond to diazoxide or octreotide. Surgical removal of the overactive part of the pancreas is curative with minimal risk when hyperinsulinism is focal or due to a benign insulin-producing tumor of the pancreas. When congenital hyperinsulinism is diffuse and refractory to medications, near-total pancreatectomy may be the treatment of last resort, but in this condition is less consistently effective and fraught with more complications.

Hypoglycemia due to hormone deficiencies such as hypopituitarism or adrenal insufficiency usually ceases when the appropriate hormone is replaced.

Hypoglycemia due to dumping syndrome and other post-surgical conditions is best dealt with by altering diet. Including fat and protein with carbohydrates may slow digestion and reduce early insulin secretion. Some forms of this respond to treatment with a glucosidase inhibitor, which slows starch digestion.

Reactive hypoglycemia with demonstrably low blood glucose levels is most often a predictable nuisance which can be avoided by consuming fat and protein with carbohydrates, by adding morning or afternoon snacks, and reducing alcohol intake.

Idiopathic postprandial syndrome without demonstrably low glucose levels at the time of symptoms can be more of a management challenge. Many people find improvement by changing eating patterns (smaller meals, avoiding excessive sugar, mixed meals rather than carbohydrates by themselves), reducing intake of stimulants such as caffeine, or by making lifestyle changes to reduce stress. See the following section of this article.

If known causes for ketotic hypoglycemia such as the ketotic Glycogen Storage Disease subtypes can be ruled out, it has been proposed that this condition simply represents the extreme edge of the normal population in terms of tolerance for fasting and ability to maintain normoglycemia. It is also possible that some children given this diagnosis have still-undiscovered defects of metabolism which will eventually be identified.

Children "outgrow" ketotic hypoglycemia, presumably because fasting tolerance improves as body mass increases. In most the episodes become milder and more infrequent by 4 to 5 years of age and rarely occur after age 9. Onset of hypoglycemia with ketosis after age 5 or persistence after age 7 should elicit referral and an intensive search for a more specific disease.

Treatment of some forms of hypoglycemia, such as in diabetes, involves immediately raising the blood sugar to normal through the ingestion of carbohydrates, determining the cause, and taking measures to hopefully prevent future episodes. However, this treatment is not optimal in other forms such as reactive hypoglycemia, where rapid carbohydrate ingestion may lead to a further hypoglycemic episode.

Blood glucose can be raised to normal within minutes by taking (or receiving) 10–20 grams of carbohydrate. It can be taken as food or drink if the person is conscious and able to swallow. This amount of carbohydrate is contained in about 3–4 ounces (100–120 ml) of orange, apple, or grape juice although fruit juices contain a higher proportion of fructose which is more slowly metabolized than pure dextrose, alternatively, about 4–5 ounces (120–150 ml) of regular (non-diet) soda may also work, as will about one slice of bread, about 4 crackers, or about 1 serving of most starchy foods. Starch is quickly digested to glucose (unless the person is taking acarbose), but adding fat or protein retards digestion. Symptoms should begin to improve within 5 minutes, though full recovery may take 10–20 minutes. Overfeeding does not speed recovery and if the person has diabetes will simply produce hyperglycemia afterwards. A mnemonic used by the American Diabetes Association and others is the "rule of 15" – consuming 15 grams of carbohydrate followed by a 15-minute wait, repeated if glucose remains low (variable by individual, sometimes 70 mg/dl).

If a person is suffering such severe effects of hypoglycemia that they cannot (due to combativeness) or should not (due to seizures or unconsciousness) be given anything by mouth, medical personnel such as paramedics, or in-hospital personnel can establish IV access and give intravenous dextrose, concentrations varying depending on age (infants are given 2 ml/kg dextrose 10%, children are given dextrose 25%, and adults are given dextrose 50%). Care must be taken in giving these solutions because they can cause skin necrosis if the IV is infiltrated, sclerosis of veins, and many other fluid and electrolyte disturbances if administered incorrectly. If IV access cannot be established, the patient can be given 1 to 2 milligrams of glucagon in an intramuscular injection. More treatment information can be found in the article diabetic hypoglycemia. If a person is suffering less severe effects, and is conscious with the ability to swallow, medical personal such as EMT-B's may administer gelatinous oral glucose.

One situation where starch may be less effective than glucose or sucrose is when a person is taking acarbose. Since acarbose and other alpha-glucosidase inhibitors prevents starch and other sugars from being broken down into monosaccharides that can be absorbed by the body, patients taking these medications should consume monosaccharide-containing foods such as glucose tablets, honey, or juice to reverse hypoglycemia.

To relieve reactive hypoglycemia, the NIH recommends taking the following steps:

- Avoiding or limiting sugar intake;

- Exercising regularly; exercise increases sugar uptake which decreases excessive insulin release

- Eating a variety of foods, including meat, poultry, fish, or nonmeat sources of protein, foods such as whole-grains, fruits, nuts, vegetables, and dairy products;

- Choosing high-fiber foods.

Other tips to prevent sugar crashes include:

- Avoiding eating meals or snacks composed entirely of carbohydrates; simultaneously ingest fats and proteins, which have slower rates of absorption.

- Consistently choosing longer lasting, complex carbohydrates to prevent rapid blood-sugar dips in the event that one does consume a disproportionately large amount of carbohydrates with a meal

- Monitoring any effects medication may have on symptoms.

Low-carbohydrate diet and/or frequent small split meals is the first treatment of this condition. The first important point is to add small meals at the middle of the morning and of the afternoon, when glycemia would start to decrease. If adequate composition of the meal is found, the fall in blood glucose is thus prevented. Patients should avoid rapidly absorbable sugars and thus avoid popular soft drinks rich in glucose or sucrose. They should also be cautious with drinks associating sugar and alcohol, mainly in the fasting state.

As it is a short-term ailment, a sugar crash does not usually require medical intervention in most people. The most important factors to consider when addressing this issue are the composition and timing of foods.

Acute low blood sugar symptoms are best treated by consuming small amounts of sweet foods, so as to regain balance in the body’s carbohydrate metabolism. Suggestions include sugary foods that are quickly digested, such as:

- Dried fruit

- Soft drinks

- Juice

- Sugar as sweets, tablets or cubes.

Acute hypoglycemia is reversed by raising the blood glucose. Glucagon should be injected intramuscularly or intravenously, or dextrose can be infused intravenously to raise the blood glucose. Oral administration of glucose can worsen the outcome, as more insulin is eventually produced. Most people recover fully even from severe hypoglycemia after the blood glucose is restored to normal. Recovery time varies from minutes to hours depending on the severity and duration of the hypoglycemia. Death or permanent brain damage resembling stroke can occur rarely as a result of severe hypoglycemia. See hypoglycemia for more on effects, recovery, and risks.

Further therapy and prevention depends upon the specific cause.

Most hypoglycemia due to excessive insulin occurs in people who take insulin for type 1 diabetes. Management of this hypoglycemia is sugar or starch by mouth (or in severe cases, an injection of glucagon or intravenous dextrose). When the glucose has been restored, recovery is usually complete. Prevention of further episodes consists of maintaining balance between insulin, food, and exercise. Management of hypoglycemia due to treatment of type 2 diabetes is similar, and the dose of the oral hypoglycemic agent may need to be reduced. Reversal and prevention of hypoglycemia is a major aspect of the management of type 1 diabetes.

Hypoglycemia due to drug overdose or effect is supported with extra glucose until the drugs have been metabolized. The drug doses or combination often needs to be altered.

Hypoglycemia due to a tumor of the pancreas or elsewhere is usually curable by surgical removal. Most of these tumors are benign. Streptozotocin is a specific beta cell toxin and has been used to treat insulin-producing pancreatic carcinoma.

Hyperinsulinism due to diffuse overactivity of beta cells, such as in many of the forms of congenital hyperinsulinism, and more rarely in adults, can often be treated with diazoxide or a somatostatin analog called octreotide. Diazoxide is given by mouth, octreotide by injection or continuous subcutaneous pump infusion. When congenital hyperinsulinism is due to focal defects of the insulin-secretion mechanism, surgical removal of that part of the pancreas may cure the problem. In more severe cases of persistent congenital hyperinsulinism unresponsive to drugs, a near-total pancreatectomy may be needed to prevent continuing hypoglycemia. Even after pancreatectomy, continuous glucose may be needed in the form of gastric infusion of formula or dextrose.

High dose glucocorticoid is an older treatment used for presumptive transient hyperinsulinism but incurs side effects with prolonged use.

The blood glucose can usually be raised to normal within minutes with 15-20 grams of carbohydrate, although overtreatment should be avoided if at all possible. It can be taken as food or drink if the person is conscious and able to swallow. This amount of carbohydrate is contained in about 3-4 ounces (100-120 mL) of orange, apple, or grape juice, about 4-5 ounces (120-150 mL) of regular (non-diet) soda, about one slice of bread, about 4 crackers, or about 1 serving of most starchy foods. Starch is quickly digested to glucose, but adding fat or protein retards digestion. Composition of the treatment should be considered, as fruit juice is typically higher in fructose which takes the body longer to metabolize than simple dextrose alone. Following treatment, symptoms should begin to improve within 5 to 10 minutes, although full recovery may take 10–20 minutes. It should be noted that over treatment does not speed recovery, and will simply produce hyperglycemia afterwards, which ultimately will need to be corrected. On the other hand, since the excess of insulin over the amount required to normalize blood sugar may continue to reduce blood sugar levels after treatment has produced an initial normalization, continued monitoring is required to determine if further treatment is necessary.

If a person cannot receive oral glucose gel or tablets, such as the case with unconsciousness, seizures, or altered mental status, then emergency personnel (EMTs/Paramedics and in-hospital personnel) can establish a peripheral or central IV line and administer a solution containing dextrose and saline. These are normally referred to as Dextrose (Concentration) Water, and come in 5%, 10%, 25% and 50%. Dextrose 5% and 10% come in IV bag and syringe form, and are mainly used in infants and to provide a fluid medium for medications. Dextrose 25% and 50% are heavily necrotic due to their hyperosmolarity, and should only be given through a patent IV line - Any infiltration can cause massive tissue necrosis. CAUTION: Dextrose 25% and 50% can easily cause necrosis in small veins. It is MUCH safer to use a Dextrose 10% solution when treating hypoglycemia via IV in children under the age of 14. When using Dextrose 25% in a child it is safer to administer it through a central line or an intra-oseous line.

If there is no hypoglycemia at the time of the symptoms, this condition is called "postprandial syndrome." It might be an "adrenergic postprandial syndrome" — blood glucose levels are normal, but the symptoms are caused through autonomic adrenergic counterregulation. Often, this syndrome is associated with emotional distress and anxious behaviour of the patient. This is often seen in dysautonomic disorders as well. Dietary recommendations for reactive hypoglycemia can help to relieve symptoms of postprandial syndrome.

The primary treatment goal is prevention of hypoglycemia and the secondary metabolic derangements by frequent feedings of foods high in glucose or starch (which is readily digested to glucose). To compensate for the inability of the liver to provide sugar, the total amount of dietary carbohydrate should approximate the 24-hour glucose production rate. The diet should contain approximately 65–70% carbohydrate, 10–15% protein, and 20–25% fat. At least a third of the carbohydrates should be supplied through the night, so that a young child goes no more than 3–4 hours without carbohydrate intake

In the last 30 years, two methods have been used to achieve this goal in young children: (1) continuous nocturnal gastric infusion of glucose or starch; and (2) night-time feedings of uncooked cornstarch. An elemental formula, glucose polymer, and/or cornstarch can be infused continuously through the night at a rate supplying 0.5–0.6 g/kg/h of glucose for an infant, or 0.3–0.4 for an older child. This method requires a nasogastric or gastrostomy tube and pump. Sudden death from hypoglycemia has occurred due to malfunction or disconnection, and periodic cornstarch feedings are now preferred to continuous infusion.

Cornstarch is an inexpensive way to provide gradually digested glucose. One tablespoon contains nearly 9 g carbohydrate (36 calories). Although it is safer, less expensive, and requires no equipment, this method does require that parents arise every 3–4 hours to administer the cornstarch. A typical requirement for a young child is 1.6 g/kg every 4 hours.

Long-term management should eliminate hypoglycemic symptoms and maintain normal growth. Treatment should achieve normal glucose, lactic acid, and electrolyte levels, and only mild elevations of uric acid and triglycerides.

Oxyhyperglycemia is most commonly caused by early dumping syndrome, but it can rarely caused by other conditions like Graves' disease. It was first described by Lawrence et al. in 1936 as often happening after gastroenterostomy. It is seen in most forms of gastrectomy, gastric bypass and gastrostomy procedures, all of which are surgical causes of dumping syndrome.

The most significant acute problem in childhood is a vulnerability to episodes of metabolic acidosis precipitated by minor illnesses. If a vomiting illness persists longer than 2–4 hours, the child should be seen and assessed for dehydration, acidosis, and hypoglycemia. If these are developing, intravenous fluids should be provided at a rate above maintenance. For mild acidosis, an effective fluid is 10% dextrose in ½ normal saline with 20 mEq/l KCl, but if acidosis is severe, 75–100 mEq/l and 20 mEq/l of K acetate can be substituted for the NaCl and KCl.

There are several genetic forms of hyperinsulinemic hypoglycemia:

Oxyhyperglycemia is a special type of impaired glucose tolerance characterized by a rapid and transient hyperglycemia (i.e. rise in blood glucose) spike after an oral intake of glucose, the peak of this spike being high enough to cause transient, symptom free glycosuria (i.e. detectable glucose in urine), but this hyperglycemia reverses rapidly and may even go to hypoglycemia in the later phase. This sharp downstroke overshooting towards hypoglycemia distinguishes this pathologic phenomenon from the artificial hyperglycemia inducible by an intravenous bolus dose of a large amount of glucose solution. Early dumping syndrome patients usually have oxyhyperglycemia associated with any meal or OGTT.

The Greek root "oxy" means "sharp" or "pointy". The OGTT curve in this condition appears sharp and somewhat pointy (at least relative to the other forms of hyperglycemia)- hence this name.

Dorlands dictionary defines oxyhyperglycemia as:

A blood level of approximately 180 mg/dL is the renal glucose threshold below which all glucose is reabsorbed from glomerular filtrate. But at blood concentrations above the renal threshold sugar starts appearing in the urine.

Oxyhyperglycemia, like other forms of Impaired glucose tolerance has also been suggested to be a prediabetic condition

Treatment depends upon the underlying cause:

- Hypoglycaemic diabetic coma: administration of the hormone glucagon to reverse the effects of insulin, or glucose given intravenously.

- Ketoacidotic diabetic coma: intravenous fluids, insulin and administration of potassium and sodium.

- Hyperosmolar diabetic coma: plenty of intravenous fluids, insulin, potassium and sodium given as soon as possible.

Although this hypothesis is well known among clinicians and individuals with diabetes, there is little scientific evidence to support it. Clinical studies indicate that a high fasting glucose in the morning is more likely because the insulin given on the previous evening fails to last long enough. Studies from 2007 onwards using continuous glucose monitoring show that a high glucose in the morning is not preceded by a low glucose during the night. Furthermore, many individuals with hypoglycemic episodes during the night don't wake due to a failure of release of epinephrine during nocturnal hypoglycemia. Thus, Somogyi's theory is not assured and may be refuted.

In terms of treatment, acute hypoglycemia is reversed by raising the blood glucose, but in most forms of congenital hyperinsulinism hypoglycemia recurs and the therapeutic effort is directed toward preventing falls and maintaining a certain glucose level. Some of the following measures are often tried:

Corn starch can be used in feeding; unexpected interruptions of continuous feeding regimens can result in sudden, hypoglycemia, gastrostomy tube insertion (requires a minor surgical procedure) is used for such feeding.Prolonged glucocorticoid use incurs the many unpleasant side effects of Cushing's syndrome, while diazoxide can cause fluid retention requiring concomitant use of a diuretic, and prolonged use causes hypertrichosis. Diazoxide works by opening the K channels of the beta cells. Octreotide must be given by injection several times a day or a subcutaneous pump must be inserted every few days, octreotide can cause abdominal discomfort and responsiveness to octreotide often wanes over time. Glucagon requires continuous intravenous infusion, and has a very short "half life".

Nifedipine is effective only in a minority, and dose is often limited by hypotension.

Pancreatectomy (removal of a portion or nearly all of the pancreas) is usually a treatment of last resort when the simpler medical measures fail to provide prolonged normal blood sugar levels. For some time, the most common surgical procedure was removal of almost all of the pancreas, this cured some infants but not all. Insulin-dependent diabetes mellitus commonly develops, though in many cases it occurs many years after the pancreatectomy.Later it was discovered that a sizeable minority of cases of mutations were focal, involving overproduction of insulin by only a portion of the pancreas. These cases can be cured by removing much less of the pancreas, resulting in excellent outcomes with no long-term problems.

Treatment is typically achieved via diet and exercise, although metformin may be used to reduce insulin levels in some patients (typically where obesity is present). A referral to a dietician is beneficial. Another method used to lower excessively high insulin levels is cinnamon as was demonstrated when supplemented in clinical human trials.

A low carbohydrate diet is particularly effective in reducing hyperinsulinism.

A healthy diet that is low in simple sugars and processed carbohydrates, and high in fiber, and vegetable protein is often recommended. This includes replacing white bread with whole-grain bread, reducing intake of foods composed primarily of starch such as potatoes, and increasing intake of legumes and green vegetables, particularly soy.

Regular monitoring of weight, blood sugar, and insulin are advised, as hyperinsulinemia may develop into diabetes mellitus type 2.

It has been shown in many studies that physical exercise improves insulin sensitivity. The mechanism of exercise on improving insulin sensitivity is not well understood however it is thought that exercise causes the glucose receptor GLUT4 to translocate to the membrane. As more GLUT4 receptors are present on the membrane more glucose is taken up into cells decreasing blood glucose levels which then causes decreased insulin secretion and some alleviation of hyperinsulinemia. Another proposed mechanism of improved insulin sensitivity by exercise is through AMPK activity. The beneficial effect of exercise on hyperinsulinemia was shown in a study by Solomon et al. (2009), where they found that improving fitness through exercise significantly decreases blood insulin concentrations.

In theory, avoidance is simply a matter of preventing hyperinsulinemia. In practice, the difficulty for a diabetic person to aggressively dose insulin to keep blood sugars levels close to normal and at the same time constantly adjust the insulin regimen to the dynamic demands of exercise, stress, and wellness can practically assure occasional hyperinsulinemia. The pharmacokinetic imperfections of all insulin replacement regimens is a severe limitation.

Some practical behaviors which are useful in avoiding chronic Somogyi rebound are:

- frequent blood glucose monitoring (8–10 times daily);

- continuous blood glucose monitoring;

- logging and review of blood glucose values, searching for patterns of low blood sugar values;

- conservative increases in insulin delivery;

- awareness to the signs of hypoglycemia;

- awareness to hyperglycemia in response to increased delivery of insulin;

- use of appropriate types of insulin (long-acting, short-acting, etc.) in appropriate amounts.

This condition has been referred to by a variety of names in the past 50 years, nesidioblastosis and islet cell adenomatosis were favored in the 1970s, beta cell dysregulation syndrome or dysmaturation syndrome in the 1980s, and persistent hyperinsulinemic hypoglycemia of infancy (PHHI) in the 1990s.

Hyperinsulinism may also refer to forms of hypoglycemia caused by excessive insulin secretion. In normal children and adults, insulin secretion should be minimal when blood glucose levels fall below 70 mg/dL (3.9 mM). There are many forms of hyperinsulinemic hypoglycemia caused by various types of insulin excess. Some of those that occur in infants and young children are termed congenital hyperinsulinism. In adults, severe hyperinsulinemic hypoglycemia is often due to an insulinoma, an insulin-secreting tumor of the pancreas.

Insulin levels above 3 μU/mL are inappropriate when the glucose level is below 50 mg/dL (2.8 mM), and may indicate hyperinsulinism as the cause of the hypoglycemia. The treatment of this form of hyperinsulinism depends on the cause and the severity of the hyperinsulinism, and may include surgical removal of the source of insulin, or a drug such as diazoxide or octreotide that reduces insulin secretion.

That spontaneous hyperinsulinism might be a cause of symptomatic hypoglycemia was first proposed by Seale Harris, MD, 1924, in "Journal of the American Medical Association".

Dr. Seale Harris first diagnosed hyperinsulinism in 1924 and also is credited with the recognition of spontaneous hypoglycemia.

Neuroglycopenia is a medical term that refers to a shortage of glucose (glycopenia) in the brain, usually due to hypoglycemia. Glycopenia affects the function of neurons, and alters brain function and behavior. Prolonged or recurrent neuroglycopenia can result in loss of consciousness, damage to the brain, and eventual death.

A rare metabolic disease of the blood-brain glucose transport system has been described in which severe neuroglycopenic effects occurred despite normal blood glucose levels. Low levels of glucose were discovered in the cerebrospinal fluid (CSF), a condition referred to as "hypoglycorrhachia" [or hypoglycorrhacia].

Hypoglycorrhachia is associated with Glucose transporter type 1 GLUT1 deficiency syndrome (GLUT1DS).

Perhaps a much more common example of the same phenomenon occurs in the people with poorly controlled type 1 diabetes who develop symptoms of hypoglycemia at levels of blood glucose which are normal for most people.

Hyperinsulinism refers to an above normal level of insulin in the blood of a person or animal. Normal insulin secretion and blood levels are closely related to the level of glucose in the blood, so that a given level of insulin can be normal for one blood glucose level but low or high for another. Hyperinsulinism can be associated with several types of medical problems, which can be roughly divided into two broad and largely non-overlapping categories: those tending toward reduced sensitivity to insulin and high blood glucose levels (hyperglycemia), and those tending toward excessive insulin secretion and low glucose levels (hypoglycemia).

The general form of this treatment is an intermediate-acting basal insulin with a regimen of food and insulin every 12 hours, with the insulin injection following the meal. The most commonly used intermediate-acting insulins are NPH, also referred to as isophane, or Caninsulin, also known as Vetsulin, a porcine Lente insulin. While the normal diabetes routine is timed feedings with insulin shots following the meals, dogs unwilling to adhere to this pattern can still attain satisfactory regulation. Most dogs do not require basal/bolus insulin injections; treatment protocol regarding consistency in the diet's calories and composition along with the established feeding and injection times is generally a suitable match for the chosen intermediate-acting insulin.

With Lantus and protamine zinc insulin (PZI) being unreliable in dogs, they are rarely used to treat canine diabetes. Bovine insulin has been used as treatment for some dogs, particularly in the UK. Pfizer Animal Health discontinued of all three types of its veterinary Insuvet bovine insulins in late 2010 and suggested patients be transitioned to Caninsulin. The original owner of the insulin brand, Schering-Plough Animal Health, contracted Wockhardt UK to produce them. Wockhardt UK has produced both bovine and porcine insulins for the human pharmaceutical market for some time.