Meaning of API in English

Meaning of API in English

According to abbreviationfinder, API stands for anterior pituitary insufficiency. In anterior pituitary insufficiency, there is a partial or complete failure of anterior pituitary hormones. These hormones include control hormones that act on other endocrine glands and effector hormones that have a direct effect on organs. The failed hormones can be substituted therapeutically.

What is anterior pituitary insufficiency?

Patients with anterior pituitary insufficiency show an axis-dependent failure of various hormones and hormonally controlled processes. The human endocrine system is a tight network. If an endocrine gland fails, this failure affects other endocrine glands, since hormones regulate each other.

The anterior pituitary forms the largest part of the pituitary gland. In this proportion, important hormones are synthesized and released into the body. In terms of shape, the anterior pituitary gland is a typical edocrine gland that mainly produces effector and control hormones. A complete or partial failure of the anterior pituitary endocrine functions is called anterior pituitary insufficiency.

Control hormones such as TSH (thyroid stimulating hormone), ACTH (adrenocorticotropic hormone), FSH (follicle stimulating hormone) and LH 1 (luteinizing hormone) have a regulating effect on other endocrine organ activities. In contrast, effector hormones such as STH (somatotropic hormone), MSH (melanocyte-stimulating hormone) and prolactin act directly on a specific effector organ.

In particular, the release of control hormones from the anterior pituitary gland is influenced by releasing and release-inhibiting hormones from the hypothalamus. If this is partially or completely disturbed, there is an anterior pituitary insufficiency, which is also referred to as hypopituitarism, Simmonds disease or HVL insufficiency.

Either certain hormones fail during the disease, or all hormones are affected by the insufficiency. In this context, a distinction is made between complete and incomplete insufficiency of the anterior pituitary lobe.


The primary causes of HVL insufficiency are extremely variable. The cause of anterior pituitary insufficiency is either destruction or displacement of pituitary tissue. HVL insufficiency also occurs when the pituitary gland is no longer connected to the hypothalamus. Such states can occur, for example, in the context of tumor diseases.

Most pituitary tumors are benign, such as hypophasic adenomas. Insufficiency can also be present after neurosurgical interventions near the pituitary structures. The same applies if tissue has been damaged by radiation therapy. The failure of the endocrine functions is often preceded by degenerative changes that cause the tissue to die off.

This can be the case, for example, in the context of stroke -related necrosis. In addition, autoimmune granulomatous processes such as sarcoidosis represent a possible cause of anterior pituitary insufficiency. In addition, hemochromatosis and all inflammatory processes can trigger the insufficiency.

Sometimes the disease is preceded by trauma, especially brain injuries. Since the hormone production of the anterior pituitary gland is influenced by the releasing and release-inhibiting hormones of the hypothalamus, a deficiency of these hormones can also be the cause of HVL insufficiency.

Symptoms, Ailments & Signs

Patients with anterior pituitary insufficiency show an axis-dependent failure of various hormones and hormonally controlled processes. The human endocrine system is a tight network. If an endocrine gland fails, this failure affects other endocrine glands, since hormones regulate each other.

If the adrenocorticotropic HVL axis fails, there is secondary adrenal insufficiency, which can manifest itself in the form of weight loss, declining performance, hypoglycemia, nausea, waxy skin structure and reduced skin pigmentation. When the control hormone axis is affected, secondary hypogonadism develops.

The secondary hair recedes. In men there is a loss of libido ], which can be associated with erectile dysfunction. Women suffer from menstrual disorders or infertility. Puberty doesn’t come. If the somatrotropic HVL axis fails, short stature can occur.

In contrast, if the thyrotropic axis is involved, secondary hypothyroidism develops, which shows the symptoms of an underactive thyroid gland, such as weight gain, intolerance to cold, bradycardia, or dry and rough skin. A prolactin deficiency plays a role especially for women and prevents breastfeeding. MSH failures cause skin pigmentation to decrease. If all of the axes mentioned are affected by failures, there is complete HVL insufficiency, which can cause a pituitary coma.

Diagnosis & course of disease

The diagnosis of anterior pituitary insufficiency is made by the doctor by examining the hormonal status. Imaging is done to find out what is causing the HVL insufficiency. In addition, as part of the diagnostics, it is checked to what extent the regulating hormones of the hypothalamus are related to the insufficiency.

In this way, causative hypothalamic insufficiencies with secondary HVL insufficiencies are differentiated from primary HVL insufficiencies. The prognosis for patients with hypopituitarism depends primarily on how many axes are affected and how long the failure has existed.


The anterior pituitary gland insufficiency primarily leads to an imbalance in hormones. This imbalance can have a negative impact on the patient’s health in general. As a rule, this leads to a sharp reduction in resilience and, not infrequently, to a loss of weight. Most of those affected also suffer from nausea and vomiting and show a changed skin structure.

The intensity of the pigmentation can also decrease. In most people, the insufficiency of the anterior lobe of the pituitary gland also leads to a reduction in hair and furthermore to erectile dysfunction, whereby women can be affected by menstrual disorders. In children, anterior pituitary insufficiency can lead to short stature. The skin becomes impure and dry as a result of this disease. In severe cases, those affected can also fall into a coma.

The patient’s immune system is also weakened, which means that various diseases develop more quickly and easily. Anterior pituitary insufficiency is usually treated with hormone therapy. This leads to a positive course of the disease relatively quickly and the symptoms disappear.

However, the patient may be dependent on this therapy for the rest of his life, since causal treatment of the anterior pituitary insufficiency is not possible. However, life expectancy is not reduced with early diagnosis and treatment.

When should you go to the doctor?

An anterior pituitary insufficiency is primarily manifested by hormonal problems. People who suddenly experience an unusual weight loss or feel ill and faint for no apparent reason should consult their family doctor . Medical advice is also required when performance decreases without a cause being identified. Nausea and vomiting, hypoglycemia and attacks of pain are symptoms that must always be examined by a doctor. Medical advice is required at the latest when there are external changes in addition to the signs mentioned.

A doctor should be consulted immediately if reduced skin pigmentation or a waxy skin structure can be detected. Affected children should be taken to the doctor if puberty is unusually long in coming. Women who suffer from menstrual disorders or infertility should discuss this with a gynaecologist . Although these symptoms do not necessarily indicate anterior pituitary insufficiency, they must be investigated and treated if necessary. Tumor patients are particularly susceptible to HVI and should inform the doctor responsible if the typical symptoms occur.

Treatment & Therapy

Anterior pituitary insufficiency is treated depending on the cause. In addition to surgical treatment options, drug therapy options are available, which usually correspond to hormone replacement therapy. Operations are mainly carried out for causative tumor diseases. Active inflammatory processes are treated with anti-inflammatory drugs.

In the case of autoimmune diseases, on the other hand, the administration of immunosuppressants is indicated, which prevents the patient’s immune system from causing further damage to the glandular tissue. For causative tumors, removal of the tumor can restore the full range of functions of the anterior pituitary gland.

On the other hand, when tissue has been damaged by inflammation, trauma, or necrosis, complete regeneration is less likely. If necessary, those affected receive lifelong hormone replacement therapy for the axes that have failed as a result of the insufficiency. If the control hormones of the anterior pituitary are absent, certain hormones are no longer produced in other glands.

In the case of hormone substitution, the patient is not given the HVL control hormones in this case. Much more the hormones are substituted, which are no longer formed by the failed control of other glands, such as testosterone, thyroxine, somatotropin or cortisol.


Anterior pituitary insufficiency can only be prevented to the extent that tumors, trauma, inflammation and other injuries to the pituitary gland and hypothalamus can be prevented.


Complete regeneration is not always possible after treatment of anterior pituitary insufficiency. Patients therefore often have to take hormone substitutes for life. These should prevent deficiency symptoms. Regular check-ups are required in consultation with the doctor.

This involves a precise examination of the hormonal situation, which enables early help. The patients need sufficient patience and discipline for the therapy and for the aftercare. Continuous improvement is only possible if you follow the doctor’s recommendations.

On the one hand, the focus is on taking the medication correctly, on the other hand, the check-ups must be carried out on time. The so-called adherence to therapy is also indispensable for long-term aftercare. Otherwise, hormone fluctuations can occur, especially in stressful phases, which have a negative effect on the state of health.

In the course of safety following the illness, the persons concerned should always carry their emergency card with them. There is also an emergency kit, useful in difficult situations. During the often lengthy recovery phase, patients should also take this set with them on day trips or longer trips to be prepared for emergencies. The aftercare mainly refers to the reduction of health risks.

You can do that yourself

If the anterior lobe of the pituitary gland is insufficient, this primarily means that the patient has to be patient and adhere to the therapy. In order to avoid the various consequences that an anterior pituitary gland insufficiency can bring about, the prescribed medication (hormones) must be taken reliably in accordance with the doctor’s instructions. This is especially true if the hormones have been prescribed in the form of sprays, gels or even injections.

In addition, the current hormone levels must be regularly reassessed and checked. The required adherence to therapy – or “compliance”, as the doctors call it – requires a lot of time and consistency, but this is the only way to avoid major failure symptoms. It is advisable to keep a detailed record of the blood tests and their results. If the patients experience unforeseen stress, the hormone levels should be remeasured as soon as possible.

In the event of an emergency, patients with pituitary insufficiency should always carry an emergency card and an emergency kit with them. This must not be forgotten, especially on vacation trips or day trips.

Patients with anterior pituitary insufficiency who have lost their body hair often suffer greatly from this cosmetic impairment. But eyebrows in particular can now be filled in with appropriate products or traced with permanent make-up.

anterior pituitary insufficiency