Thyroid hormone resistance syndrome is rare, incidence is variously quoted as 1 in 50,000 or 1 in 40,000 live births. More than 1000 individuals have been identified with thyroid hormone resistance, of which 85% had thyroid hormone beta receptor mutation.

Beta blockers, like Atenolol, are sometimes used to help suppress symptoms.

The primary current medical treatment of acromegaly is to use somatostatin analogues – octreotide (Sandostatin) or lanreotide (Somatuline).

These somatostatin analogues are synthetic forms of a brain hormone, somatostatin, which stops GH production. The long-acting forms of these drugs must be injected every 2 to 4 weeks for effective treatment. Most patients with acromegaly respond to this medication. In many patients, GH levels fall within one hour and headaches improve within minutes after the injection. Octreotide and lanreotide are effective for long-term treatment. Octreotide and lanreotide have also been used successfully to treat patients with acromegaly caused by non-pituitary tumors.

Somatostatin analogues are also sometimes used to shrink large tumors before surgery.

Because octreotide inhibits gastrointestinal and pancreatic function, long-term use causes digestive problems such as loose stools, nausea, and gas in one third of patients. In addition, approximately 25 percent of patients develop gallstones, which are usually asymptomatic. In some cases, octreotide treatment can cause diabetes due to the fact that somatostatin and its analogues can inhibit the release of insulin.

For those who are unresponsive to somatostatin analogues, or for whom they are otherwise contraindicated, it is possible to treat using one of the dopamine agonists, bromocriptine or cabergoline. As tablets rather than injections, they cost considerably less. These drugs can also be used as an adjunct to somatostatin analogue therapy. They are most effective in those whose pituitary tumours cosecrete prolactin. Side effects of these dopamine agonists include gastrointestinal upset, nausea, vomiting, light-headedness when standing, and nasal congestion. These side effects can be reduced or eliminated if medication is started at a very low dose at bedtime, taken with food, and gradually increased to the full therapeutic dose. However, bromocriptine lowers GH and IGF-1 levels and reduces tumor size in fewer than half of patients with acromegaly. Some patients report improvement in their symptoms although their GH and IGF-1 levels still are elevated.

People with autoimmune hyperthyroidism should not eat foods high in iodine, such as edible seaweed and kelps.

From a public health perspective, the general introduction of iodized salt in the United States in 1924 resulted in lower disease, goiters, as well as improving the lives of children whose mothers would not have eaten enough iodine during pregnancy which would have lowered the IQs of their children.

There is little evidence whether there is a benefit from treating subclinical hypothyroidism, and whether this offsets the risks of overtreatment. Untreated subclinical hypothyroidism may be associated with a modest increase in the risk of coronary artery disease. A 2007 review found no benefit of thyroid hormone replacement except for "some parameters of lipid profiles and left ventricular function". There is no association between subclinical hypothyroidism and an increased risk of bone fractures, nor is there a link with cognitive decline.

Since 2008, consensus American and British opinion has been that in general people with TSH under 10 mIU/l do not require treatment. American guidelines recommend that treatment should be considered if the TSH is elevated but below 10 mIU/l in people with symptoms of hypothyroidism, detectable antibodies against thyroid peroxidase, a history of heart disease or are at an increased risk for heart disease.

Desiccated thyroid extract is an animal-based thyroid gland extract, most commonly from pigs. It is a combination therapy, containing forms of T and T. It also contains calcitonin (a hormone produced in the thyroid gland involved in the regulation of calcium levels), T and T; these are not present in synthetic hormone medication. This extract was once a mainstream hypothyroidism treatment, but its use today is unsupported by evidence; British Thyroid Association and American professional guidelines discourage its use.

Levothyroxine is a stereoisomer of thyroxine (T4) which is degraded much more slowly and can be administered once daily in patients with hypothyroidism. Natural thyroid hormone from pigs is sometimes also used, especially for people who cannot tolerate the synthetic version. Hyperthyroidism caused by Graves' disease may be treated with the thioamide drugs propylthiouracil, carbimazole or methimazole, or rarely with Lugol's solution. Additionally, hyperthyroidism and thyroid tumors may be treated with radioactive iodine. Ethanol injections for the treatment of recurrent thyroid cysts and metastatic thyroid cancer in lymph nodes can also be an alternative to surgery.

Radioiodine therapy with iodine-131 can be used to shrink the thyroid gland (for instance, in the case of large goiters that cause symptoms but do not harbor cancer—after evaluation and biopsy of suspicious nodules has been done), or to destroy hyperactive thyroid cells (for example, in cases of thyroid cancer). The iodine uptake can be high in countries with iodine deficiency, but low in iodine sufficient countries. To enhance iodine-131 uptake by the thyroid and allow for more successful treatment, TSH is raised prior to therapy in order to stimulate the existing thyroid cells. This is done either by withdrawal of thyroid hormone medication or injections of recombinant human TSH (Thyrogen), released in the United States in 1999. Thyrogen injections can reportedly boost uptake up to 50-60%. Radioiodine treatment can also cause hypothyroidism (which is sometimes the end goal of treatment) and, although rare, a pain syndrome (due to radiation thyroiditis).

Surgery (thyroidectomy to remove the whole thyroid or a part of it) is not extensively used because most common forms of hyperthyroidism are quite effectively treated by the radioactive iodine method, and because there is a risk of also removing the parathyroid glands, and of cutting the recurrent laryngeal nerve, making swallowing difficult, and even simply generalized staphylococcal infection as with any major surgery. Some people with Graves' may opt for surgical intervention. This includes those that cannot tolerate medicines for one reason or another, people that are allergic to iodine, or people that refuse radioiodine.

If people have toxic nodules treatments typically include either removal or injection of the nodule with alcohol.

The main strategies for the management of thyroid storm are reducing production and release of thyroid hormone, reducing the effects of thyroid hormone on tissues, replacing fluid losses, and controlling temperature. Thyroid storm requires prompt treatment and hospitalization. Often, admission to the intensive care unit is needed.

Iodine

Guidelines recommend the administration of inorganic iodide (potassium iodide or Lugol's iodine) to reduce the synthesis and release of thyroid hormone. Iodine reduces the synthesis of thyroid hormone via the Wolf-Chaikoff effect. Some guidelines recommend that iodine be administered after antithyroid medications are started, because iodine is also a substrate for the synthesis of thyroid hormone, and may worsen hyperthyroidism if administered without antithyroid medications.

Antithyroid Medications

Antithyroid drugs (propylthiouracil or methimazole) are used to reduce the synthesis and release of thyroid hormone. Propylthiouracil is preferred over methimazole due to its additional effects on reducing peripheral conversion of T4 to T3, however both are commonly used.

Beta Blockers

The administration of beta-1-selective beta blockers (e.g. propranolol) is recommended to reduce the effect of circulating thyroid hormone on end organs. In addition, propanolol at high doses also reduces peripheral conversion of T4 to T3, which is the more active form of thyroid hormone. Although previously unselective beta blockers (e.g., propranolol) have been suggested to be beneficial due to their inhibitory effects on peripheral deiodinases recent research suggests them to be associated with increased mortality. Therefore, cardioselective beta blockers may be favourable.

Corticosteroids

High levels of thyroid hormone result in a hypermetabolic state, which can result in increased breakdown of cortisol, a hormone produced by the adrenal gland. This results in a state of relative adrenal insufficiency, in which the amount of cortisol is not sufficient. Guidelines recommend that corticosteroids (hydrocortisone and dexamethasone are preferred over prednisolone or methylprednisolone) be administered to all patients with thyroid storm. However, doses should be altered for each individual patient to ensure that the relative adrenal insufficiency is adequately treated while minimizing the risk of side effects.

Supportive Measures

In high fever, temperature control is achieved with fever reducers such as paracetamol/acetaminophen and external cooling measures (cool blankets, ice packs). Dehydration, which occurs due to fluid loss from sweating, diarrhea, and vomiting, is treated with frequent fluid replacement. In severe cases, mechanical ventilation may be necessary. Any suspected underlying cause is also addressed.

Toxic multinodular goiter can be treated with antithyroid medications such as propylthiouracil or methimazole, radioactive iodine, or with surgery.

Another treatment option is injection of ethanol into the nodules.

In endocrinology, medical emergencies include diabetic ketoacidosis, hyperosmolar hyperglycemic state, hypoglycemic coma, acute adrenocortical insufficiency, phaeochromocytoma crisis, hypercalcemic crisis, thyroid storm, myxoedema coma and pituitary apoplexy.

Emergencies arising from decompensated pheochromocytomas or parathyroid adenomas are sometimes referred for emergency resection when aggressive medical therapies fail to control the patient's state, however the surgical risks are significant, especially blood pressure lability and the possibility of cardiovascular collapse after resection (due to a brutal drop in respectively catecholamines and calcium, which must be compensated with gradual normalization). It remains debated when emergency surgery is appropriate as opposed to urgent or elective surgery after continued attempts to stabilize the patient, notably in view of newer and more efficient medications and protocols.

Goitre is treated according to the cause. If the thyroid gland is producing too much T3 and T4, radioactive iodine is given to the patient to shrink the gland. If goitre is caused by iodine deficiency, small doses of iodide in the form of Lugol's Iodine or KI solution are given. If the goitre is associated with an underactive thyroid, thyroid supplements are used as treatment. In extreme cases, a partial or complete thyroidectomy is required.

Severe hypocalcaemia, a potentially life-threatening condition, is treated as soon as possible with intravenous calcium (e.g. as calcium gluconate). Generally, a central venous catheter is recommended, as the calcium can irritate peripheral veins and cause phlebitis. In the event of a life-threatening attack of low calcium levels or tetany (prolonged muscle contractions), calcium is administered by intravenous (IV) infusion. Precautions are taken to prevent seizures or larynx spasms. The heart is monitored for abnormal rhythms until the person is stable. When the life-threatening attack has been controlled, treatment continues with medicine taken by mouth as often as four times a day.

Long-term treatment of hypoparathyroidism is with vitamin D analogs and calcium supplementation, but may be ineffective in some due to potential renal damage. The N-terminal fragment of parathyroid hormone (PTH 1-34) has full biological activity. The use of pump delivery of synthetic PTH 1-34 provides the closest approach to physiologic PTH replacement therapy. Injections of recombinant human parathyroid hormone are available as treatment in those with low blood calcium levels.

Goitre is more common among women, but this includes the many types of goitre caused by autoimmune problems, and not only those caused by simple lack of iodine.

Hypothalamic disease is a disorder presenting primarily in the hypothalamus, which may be caused by damage resulting from malnutrition, including anorexia and bulimia eating disorders, genetic disorders, radiation, surgery, head trauma, lesion, tumour or other physical injury to the hypothalamus. The hypothalamus is the control center for several endocrine functions. Endocrine systems controlled by the hypothalamus are regulated by anti-diuretic hormone (ADH), corticotropin-releasing hormone, gonadotropin-releasing hormone, growth hormone-releasing hormone, oxytocin, all of which are secreted by the hypothalamus. Damage to the hypothalamus may impact any of these hormones and the related endocrine systems. Many of these hypothalamic hormones act on the pituitary gland. Hypothalamic disease therefore affects the functioning of the pituitary and the target organs controlled by the pituitary, including the adrenal glands, ovaries and testes, and the thyroid gland.

Numerous dysfunctions manifest as a result of hypothalamic disease. Damage to the hypothalamus may cause disruptions in body temperature regulation, growth, weight, sodium and water balance, milk production, emotions, and sleep cycles. Hypopituitarism, neurogenic diabetes insipidus, tertiary hypothyroidism, and developmental disorders are examples of precipitating conditions caused by hypothalamic disease.

Growth hormone-releasing hormone (GHRH) is another releasing factor secreted by the hypothalamus. GHRH stimulates the pituitary gland to secrete growth hormone (GH), which has various effects on body growth and sexual development. Insufficient GH production may cause poor somatic growth, precocious puberty or gonadotropin deficiency, failure to initiate or complete puberty, and is often associated with rapid weight gain, low T, and low levels of sex hormones.

The usage of terminology for types of goiter has varied over the past century. Physicians and surgeons tend to differentiate among solitary-nodule goiter, multinodular goiter, and non-nodular goiter more thoroughly in recent decades than they formerly did. Thus some sources have described, or still describe, thyroid adenoma (toxic adenoma) as synonymous with toxic multinodular goiter, but other sources differentiate those two as single-nodule disease versus multinodular disease (respectively) with pathogenesis that is likely differing in most cases (eg, single neoplastic cell clone versus multifocal or diffuse molecular metabolic change). The medical eponyms "Plummer disease" (named after American physician Henry Stanley Plummer) and "Parry disease" (named after English physician Caleb Hillier Parry) have been used to refer to toxic multinodular goiter, toxic adenoma, and toxic diffuse goiter (Graves' disease); the specific entity in each patient/case is not always clear retrospectively, especially in older literature. This is logical given that advanced medical imaging that can show what is happening at various places within a thyroid gland inside a living person (such as nuclear medicine imaging of radioiodine tracer uptake) was not available until after the 1940s.

Most children born with congenital hypothyroidism and correctly treated with thyroxine grow and develop normally in all respects. Even most of those with athyreosis and undetectable T levels at birth develop with normal intelligence, although as a population academic performance tends to be below that of siblings and mild learning problems occur in some.

Congenital hypothyroidism is the most common preventable cause of intellectual disability. Few treatments in the practice of medicine provide as large a benefit for as small an effort.

The developmental quotient (DQ, as per Gesell Developmental Schedules) of children with hypothyroidism at age 24 months that have received treatment within the first 3 weeks of birth is summarised below:

The goal of newborn screening programs is to detect and start treatment within the first 1–2 weeks of life. Treatment consists of a daily dose of thyroxine, available as a small tablet. The generic name is levothyroxine, and several brands are available. The tablet is crushed and given to the baby with a small amount of water or milk. The most commonly recommended dose range is 10-15 μg/kg daily, typically 12.5 to 37.5 or 44 μg.

Within a few weeks, the T and TSH levels are rechecked to confirm that they are being normalized by treatment. As the child grows up, these levels are checked regularly to maintain the right dose. The dose increases as the child grows.

Levofloxacin does pass through breast milk. It is not likely to cause problems for the baby. In some cases, an underactive thyroid may inhibit the production of breast milk.

Endocrine diseases are disorders of the endocrine system. The branch of medicine associated with endocrine disorders is known as endocrinology.

All causes in this category are genetic, and generally very rare. These include mutations to the "SF1" transcription factor, congenital adrenal hypoplasia due to "DAX-1" gene mutations and mutations to the ACTH receptor gene (or related genes, such as in the Triple A or Allgrove syndrome). "DAX-1" mutations may cluster in a syndrome with glycerol kinase deficiency with a number of other symptoms when "DAX-1" is deleted together with a number of other genes.

A pituitary disease is a disorder primarily affecting the pituitary gland.

The main disorders involving the pituitary gland are:

Overproduction or underproduction of a pituitary hormone will affect the respective end-organ. For example, insufficient production (hyposecretion) of thyroid stimulating hormone (TSH) in the pituitary gland will cause hypothyroidism, while overproduction (hypersecretion) of TSH will cause hyperthyroidism. Thyroidisms caused by the pituitary gland are less common though, accounting for less than 10% of all hypothyroidism cases and much less than 1% of hyperthyroidism cases.